How to Find a Good Ladle Shroud Supplier from China

In modern continuous casting operations, the ladle shroud plays a critical role in ensuring smooth steel flow, minimizing re-oxidation, and stabilizing casting quality. As global steel plants increasingly rely on China for high-quality refractory components, choosing a reliable ladle shroud supplier from China has become a key factor that directly affects safety, casting stability, product quality, and overall cost efficiency.
However, China has hundreds of refractory manufacturers, and the quality varies dramatically—from world-class exporters to small workshops. Selecting the right supplier requires a systematic evaluation, technical understanding, and due diligence.
This article provides a detailed, practical, and highly technical guide on how to find a good ladle shroud supplier from China, covering quality indicators, manufacturing capabilities, materials, inspection standards, pricing logic, delivery systems, and supplier verification.


ladle shroud
1. Understand What Makes a High-Quality Ladle Shroud
Before selecting a supplier, buyers should clearly understand what distinguishes a good ladle shroud from an average one. A professional ladle shroud must meet the following requirements:
1.1 Excellent Material Formula
High-quality ladle shrouds typically use:
Alumina-Carbon (Al-C)
Alumina-Graphite
Zirconia-Carbon (ZrO‚-C)
Spinel-Carbon
High-purity fused alumina with antioxidants
The supplier must have stable raw material sources and advanced formulation technology to ensure:
High thermal shock resistance
Strong slag corrosion resistance
High mechanical strength
Stable flow-control performance
Minimal oxidation loss
1.2 Precision Dimensional Tolerance
A good ladle shroud must align precisely with the upper nozzle and tundish shroud manipulator.
Dimensional accuracy directly affects:
Steel flow stability
Nozzle alignment
Casting safety
Most high-level suppliers can control tolerance within ±1 mm, while inferior suppliers exceed ±3–5 mm.
1.3 Uniform Density and Microstructure
Uniform density ensures:
No internal cracks
No weak layers
Long service life
Suppliers with advanced isostatic pressing or high-pressure forming equipment usually provide more reliable products.
2. Identify What Separates Top-Tier Chinese Ladle Shroud Manufacturers
China's refractory industry is large, but only a fraction of companies meet international technical and quality levels. When sourcing, the following indicators help you find the right supplier:
2.1 Manufacturing Equipment Level
High-quality suppliers use:
2000–3000 ton isostatic pressing machines
High-precision CNC machining equipment
Fully automated mixing and batching systems
Advanced firing kilns with precise temperature control
Small workshops typically use outdated hydraulic presses and manual processes, leading to poor consistency and unstable quality.
2.2 Technical R&D Capability
A strong supplier has:
Independent R&D team
Ability to customize ladle shrouds for different steel grades
Capability to design anti-oxidation systems and slag-resistant materials
Ability to solve on-site technical problems (slag sticking, nozzle erosion, shroud clogging, etc.)
2.3 Quality Control System
Check if the supplier has:
ISO 9001
Internal product tracking system
Digital QC records
Raw material test reports
Density testing, ultrasonic flaw detection, and physical property tests
A top supplier must provide:
 Bulk density
 Apparent porosity
 Cold crushing strength
 Thermal shock resistance
 Slag corrosion test results
If a supplier cannot provide these reports, avoid them.
3. Evaluate the Supplier’s Production Stability and Export Experience
A reliable ladle shroud manufacturer should have:
3.1 Stable Production Capacity
Ask:
Annual output capacity
Peak delivery capacity
Ability to support long-term production without delay
Whether they have backup raw material stock
3.2 Export Experience
Exporters familiar with European, Middle Eastern, Indian, and South American markets usually:
Have stable product quality
Understand international shipment and packing standards
Offer more professional documentation support
Check:
Past export records
Cooperation with major steel plants
Customer feedback or case studies
3.3 Certifications and Compliance
Depending on your market, check if they meet:
EN, ISO standards
Environmental protection and safety standards
Test results for anti-oxidation performance
4. How to Verify a Chinese Supplier Before Placing an Order
4.1 Conduct Factory Audit
If possible, visit the factory in person or appoint a third-party inspection company.
Check:
Workshop cleanliness
Equipment age and automation
Storage of raw materials
Firing kiln condition
Finished products warehouse
Ongoing production orders
4.2 Request Technical Documentation
A good supplier will provide:
Technical data sheets
Material composition
Recommended operating parameters
Compatible shroud manipulator dimensions
Casting performance reports
Sample test report from third-party labs
4.3 Request Samples for Evaluation
Before mass order, evaluate:
Visual appearance
Weight and density
Dimensional accuracy
Finish quality
Microstructure
Thermal shock test
On-site trial in real casting
4.4 Conduct Supplier Background Research
Check:
Company registration information
Years of operation
Employee count
Export license
Official website
Customer comments on industry forums


ladle shroud
5. Understand the Real Pricing of Ladle Shrouds in China
Price varies according to:
5.1 Raw Material Grade
For example:
Fused alumina vs. sintered alumina
High-purity graphite vs. low-purity graphite
ZrO‚ content differences (e.g., 6% vs 12%)
5.2 Forming Method
Isostatically pressed products cost more but are more stable
Hydraulic press products are cheaper but quality fluctuates
5.3 Anti-oxidation System
Better antioxidants such as Al, Mg, SiC, or special additives will increase cost but greatly enhance performance.
5.4 Packaging and Logistics
Export-standard packaging (steel pallet + fumigation-free wood + seaworthy protection) adds value.
5.5 Brand Reputation
Old, reputable factories cost slightly more, but:
quality is stable
delivery is reliable
after-sales support is better
Avoid choosing the lowest price—that usually means weak materials, poor density, or unstable performance.
6. Red Flags: How to Identify an Unreliable Supplier
Be cautious if you notice any of the following:
Very low prices without technical explanation
Cannot provide detailed drawings and formula
Refusing factory visit
No QC documents
No export experience
Response too slow or unprofessional
Delivery time promise is unrealistic
Photos look inconsistent or downloaded from internet
These issues often indicate middlemen or low-level workshops.
7. Key Questions to Ask a Chinese Ladle Shroud Supplier
Before final confirmation, ask:
What is your forming method? (ISO-press or HP press?)
What is the exact material composition?
What antioxidants are used?
Can you provide test reports from the last three batches?
What is the guaranteed service life in continuous casting?
Can you produce custom sizes to match our manipulator?
How do you control density uniformity?
How long is your delivery time?
What packaging do you use for export?
Can you support on-site technical service and troubleshooting?
A professional supplier will answer in detail and confidently.
Conclusion: The Best Strategy to Find a Reliable Ladle Shroud Supplier in China
Finding a good ladle shroud supplier from China is not difficult if the process is systematic. The key factors include:
Evaluate material quality and technical capability
Confirm production equipment and factory scale
Review quality control systems and test reports
Understand export experience and packaging standards
Conduct sample inspections and on-site trials
Avoid suppliers offering suspiciously low prices
Prioritize stability, consistency, and long-term reliability
A top Chinese supplier should not only provide high-quality ladle shrouds but also offer:
 Technical support
 On-site casting solutions
 Customized design
 Reliable long-term cooperation
Selecting the right partner will significantly improve casting safety, reduce operational risks, and enhance steel quality.More information ,please visit HYRE

Oznake: ladle shroud

Treatment Measures for Ladle Crack and Leakage

Description

The ladle nozzle block in the steelmaking plant continuously produces cracks during use, which seriously affects the service life of the ladle and restricts on-site production. Adjustments were made in terms of the quality of the block itself, the construction and baking of castables around the block, the temperature drop during the ladle turnover process, and the operation of replacing the nozzle. Corrective measures were put forward for possible affecting links, and subsequent hidden dangers were gradually eliminated, and satisfactory results were achieved.

The ladle nozzle block in the steelmaking plant continuously produces cracks during use, which seriously affects the service life of the ladle and restricts on-site production. By comparing several nozzle seat bricks, adjustments were made in terms of the quality of the seat brick itself, the construction and baking of castables around the seat brick, the temperature drop during the ladle turnover process, and the operation of replacing the nozzle, and proposed rectification measures for the possible impact links, gradually eliminating subsequent hidden dangers , with satisfactory results.

The role of the steel ladle in the steelmaking plant is to transport the molten steel smelted in the converter to the continuous casting. On the turret of the continuous casting ladle, the 1500°C high-temperature molten steel flows out into the tundish through the nozzle and slide plate at the bottom of the ladle, and the billet transfer is suspended. Finally, it flows out from the tundish nozzle to the continuous casting and straightening, and the billet forming is completed. For the nozzle where the high-temperature molten steel flows out from the ladle, it needs to be placed inside the nozzle block. During the use of the ladle, the nozzle can be replaced online after 20-25 times of use. The nozzle block must be replaced when the ladle is repaired. Replace the nozzle block. The quality of the nozzle seat brick and the quality of the construction directly affect whether the ladle can operate normally. The quality problems of ladle nozzle seat bricks during operation usually include unstable materials, problems in knotting process control, inadequate baking, and defects in on-site construction and installation. This paper sorts out and solves the problems of the on-site nozzle block, and finally achieves satisfactory results, ensuring the normal operation of the ladle.

On-site situation of ladle use
The steelmaking plant uses a 150-ton ladle with double nozzles, and the nozzles are directly embedded in the seat brick. The seat brick is installed at the bottom of the ladle when the bottom magnesia-carbon brick is built. The service life is synchronized with the bottom of the ladle. The service life of the entire ladle is between 130-150 furnaces, and the schematic diagram of the overall refractory material of the ladle is shown in Figure 1 below;

Treatment Measures for Ladle Crack and Leakage
The ladle nozzle is installed before the ladle is baked and put on the line. The sealing glue is applied to the outside of the nozzle, and the nozzle is embedded into the inside of the block by manual use of strong pressure, so that the block, the mortar and the nozzle are closely connected as a whole, increasing the overall strength. The specific installation diagram is shown in Figure 2 below. During the use of the block, the uppermost part of the block directly contacts the initial impact of the molten steel, and the continuous erosion and erosion of the molten steel flow out. The length of the block is getting shorter and shorter. The nozzle in the block It is the direct outflow channel of molten steel, which bears the impact and friction of high-temperature molten steel and the temperature difference change in the production process. The connection between him and the seat brick is sealed by the sealing glue between them.

Treatment Measures for Ladle Crack and Leakage
From July to September, cracks in the nozzle block appeared one after another. It was found that the off-line treatment was carried out in time, and it was found that the steel was not penetrated through the cement channel between the nozzle and the block in time, which seriously restricted the on-site production rhythm. The cost of ladle is increased, and the production is in a passive situation. The following figure 3 shows the accident of Zizi steel sheathing caused by the crack of the seat brick, and figure 4 shows the crack of the seat brick observed online.

Treatment Measures for Ladle Crack and Leakage
In view of the steel leakage accident between the channel of the seat brick and the nozzle caused by the crack of the seat brick, the quality of the nozzle, composition, quality of the seat brick, construction and other aspects are analyzed and tracked one by one. The reason can be ruled out if the nozzle is intact; Cracks are found, the analysis is mainly due to cracks in the seat brick, the integrity is incomplete, and the strength decreases. At the same time, the gap between the seat brick and the nozzle increases, and the molten steel penetrates into the gap of the cement, and the seat brick, cement and nozzle are integrated. The overall strength is destroyed, and the sealing cement cannot withstand the hot molten steel at high temperature, and is gradually corroded, resulting in steel seeding and steel leakage accidents.

Measures taken against steel breakout
As for the steel breakout accident caused by the cracks in the block bricks, the personnel of the steelmaking plant and the technical center combined with the manufacturer to analyze the reasons. On the one hand, the material of the block blocks was analyzed and adjusted by the manufacturer, and at the same time, the quality and quality were urgently dispatched from other domestic block block manufacturers. The company’s products with good reputation are tested, the situation is as follows:

Treatment Measures for Ladle Crack and Leakage
1) The seat brick of manufacturer A was used on site, and after using it in the later stage (about 60 times), micro-cracks were found, and the upper part of the seat brick had obvious diameter expansion;

2) The seat brick of manufacturer B was offline, and there were many longitudinal micro-cracks, and the cracks were distributed at 90 degrees in the middle of the seat brick (from the ladle hot repair platform, the personnel facing the seat brick were used as a horizontal reference, and the cracks were not in the seat brick. the four corners of the ).

3) The ladle contractor analyzed the material of the seat brick, selected high-quality raw materials and carried out the formula operation step by step. decrease;

The measures taken for the installation and operation of block bricks are as follows:

The seat bricks are built together with the bottom of the package during installation. Before the seat bricks are installed and positioned, the steel structure at the bottom of the seat bricks is cleaned of impurities and filled, and the surrounding area is vibrated and filled with castables. Baking is carried out after the overall construction is completed. Baking, online, the specific schematic diagram is shown in the figure below:
1) Strictly control the water-cement ratio of the castable around the base brick, and control the moisture between 6-8%.

2) Castable construction: For the gap (30-100mm) between the seat brick and the bottom of the package, manual operation is used in the vibration process, and vibrating rods cannot be used to vibrate, so as to avoid excessive vibration force and aggregate sinking.

3) When replacing the nozzle online, check the cracks and erosion of the seat brick.

4) Frequently contact the dispatcher, and the time for the steel ladle to come off the assembly line exceeds 30 minutes, and a second baking should be carried out.

5) Strictly monitor the temperature when the ladle is baked, and designate a special record book to mainly record the temperature of each part (the bottom of the ladle, the wall of the ladle, the slag line, and the mouth of the ladle), and pay close attention to the exhaust at the nozzle of the ladle and the wall of the ladle during baking. situation.
Choose HYFR, Choose the top quality of China!
Choose HYRE, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!

Oznake: slide gate plate, ladle shroud, tundish stopper, sen

Key Factors Impacting ladle refractory materials Lifespan

Refractory materials for ladles account for more than 30% of iron and steel metallurgical refractory materials and are the focus of metallurgical refractory material consumption. At present, ordinary small ladles use aluminum-magnesia castables with high aluminum as the main raw material. The service life has reached more than 70 times, and the good ones have reached more than 150 times. Especially when the cold repair mode of cold peeling and then casting restoration is adopted, And repeat.

For medium and large ladles, magnesia-carbon bricks are generally used for the slag line, and corundum-spinel or alumina-magnesia castables or alumina-magnesia carbon bricks are used for other parts. And 2 or 3 slag lines and bottom bricks are balanced with 1 molten pool lining, so that the unit consumption of refractory materials is 2~4kg/t. However, there are also low-grade brick-built ladles with low service life, no repairs, and one-time replacement, resulting in high unit consumption of refractory materials.

As the quality of steel products improves, an increasing proportion of processes such as argon blowing and stirring, oxygen blowing to decarburize, heating, slag addition, alloying elements, and vacuum are required to be carried out in the ladle. These processes lead to longer and longer residence times of molten steel in the ladle, accelerated erosion of the refractory lining and a significant reduction in service life.

This study analyzes and discusses the impact of each refining process parameter on the lining, revealing their influence rules. These rules are used to combine the operating conditions with improving the service life of the ladle to achieve the purpose of increasing the service life of the ladle and reducing the unit consumption of refractory materials.

Effect of usage conditions on corrosion of lining refractory materials

1. Effect of temperature

The relationship between the dissolution rate of the ladle lining refractory material and temperature. When the temperature of the molten steel in the ladle is higher, the dissolution and erosion will be faster and the service life will be shorter. Researchers conducted a systematic study on the resistance of refining ladle materials to slag dissolution and obtained very instructive conclusions.

The increase in the temperature of the molten steel in the ladle significantly increases the erosion rate. An important process of ladle refining is that the input of heat energy such as arc heating, electromagnetic stirring heating, adding exothermic agent or oxygen blowing increases the temperature of the ladle, resulting in accelerated erosion of the ladle lining and reduced service life. This is one of the important reasons why the service life of refining equipment such as VOD and LF is significantly lower than that of ordinary ladles.

On the other hand, temperature uniformity is also an important factor affecting the service life and safety of refining ladles. For the LF furnace, arc heating leads to local hot spots and accelerated damage. Without repair, the fastest erosion determines the service life, thus leading to a reduction in the service life of the ladle. In this case, reducing the continuous heating time and appropriately reducing the heating intensity is very effective in reducing hot spot overheating and increasing the service life of the ladle lining. In addition, timely repairs and balanced ladle lining are required.

2. Influence of filling time of molten steel

Under normal circumstances, molten steel hardly dissolves refractory materials, or molten steel dissolves refractory materials very slowly. The corrosion of refractory materials in ladles is mainly caused by slag.

The effect of molten steel on refractory materials is mainly reflected in three aspects:

First, during the processes of tapping, pouring, and argon blowing and stirring, the flow rate and impact force of the molten steel are very large, eroding the refractory lining, resulting in refractory material loss and refractory particles entering the molten steel. Most of the refractory particles entering the molten steel float to the slag, while a small number of tiny particles cannot float and form non-metallic inclusions in the steel, which affects the quality of the steel.

The second is that the lining refractory material dissolves into the molten steel. Generally, the solubility of refractory materials in steel is very low, and there is little dissolution and erosion. However, some components (such as carbon) in refractory materials have high solubility in steel and dissolve into steel, which affects the production of low carbon steel and ultra-low carbon steel.

Third, certain components of the refractory material interact with certain components in the molten steel (especially some special steel components), causing chemical reactions, resulting in changes in the steel composition and erosion of the refractory material.

The residence time of molten steel in the ladle is divided into tapping time (2 to 7 minutes), refining time, residence time and steel pouring time. The degree of erosion of the refractory lining during these periods is different. During the tapping process, the impact of the molten steel on the lining causes local erosion loss. At the same time, the strong stirring causes the reaction corrosion between the slag and the refractory material to be intense. During the refining process, the longer the refining time, the more the slag reacts with the refractory material, and the greater the corrosion amount, that is, the lower the service life of the ladle. The service life of the ladle lining decreases linearly with the extension of the refining time. During the residence period, as the time prolongs, the interface reaction layer thickens, and the reactants and products need to diffuse for a long time. The erosion is controlled by diffusion.

According to the diffusion kinetic equation, the amount of erosion is proportional to the square root of the residence time. Therefore, the lining refractory material erodes slowly during the residence period. During the steel pouring process, slag rises up and falls through different positions of the ladle, which is the main cause of erosion of the ladle molten pool. However, during the steel pouring process, the contact time between the slag and the lining somewhere is very short, so the erosion of the lining during the steel pouring process is still very small.

2. Influence of filling time of molten steel

Under normal circumstances, molten steel hardly dissolves refractory materials, or molten steel dissolves refractory materials very slowly. The corrosion of refractory materials in ladles is mainly caused by slag.

The effect of molten steel on refractory materials is mainly reflected in three aspects:

First, during the processes of tapping, pouring, and argon blowing and stirring, the flow rate and impact force of the molten steel are very large, eroding the refractory lining, resulting in refractory material loss and refractory particles entering the molten steel. Most of the refractory particles entering the molten steel float to the slag, while a small number of tiny particles cannot float and form non-metallic inclusions in the steel, which affects the quality of the steel.

The second is that the lining refractory material dissolves into the molten steel. Generally, the solubility of refractory materials in steel is very low, and there is little dissolution and erosion. However, some components (such as carbon) in refractory materials have high solubility in steel and dissolve into steel, which affects the production of low carbon steel and ultra-low carbon steel.

Third, certain components of the refractory material interact with certain components in the molten steel (especially some special steel components), causing chemical reactions, resulting in changes in the steel composition and erosion of the refractory material.

The residence time of molten steel in the ladle is divided into tapping time (2 to 7 minutes), refining time, residence time and steel pouring time. The degree of erosion of the refractory lining during these periods is different. During the tapping process, the impact of the molten steel on the lining causes local erosion loss. At the same time, the strong stirring causes the reaction corrosion between the slag and the refractory material to be intense. During the refining process, the longer the refining time, the more the slag reacts with the refractory material, and the greater the corrosion amount, that is, the lower the service life of the ladle. The service life of the ladle lining decreases linearly with the extension of the refining time. During the residence period, as the time prolongs, the interface reaction layer thickens, and the reactants and products need to diffuse for a long time. The erosion is controlled by diffusion.

According to the diffusion kinetic equation, the amount of erosion is proportional to the square root of the residence time. Therefore, the lining refractory material erodes slowly during the residence period. During the steel pouring process, slag rises up and falls through different positions of the ladle, which is the main cause of erosion of the ladle molten pool. However, during the steel pouring process, the contact time between the slag and the lining somewhere is very short, so the erosion of the lining during the steel pouring process is still very small.

Key Factors Impacting ladle refractory materials Lifespan
3.2. Influence of slag oxidation

At present, magnesia carbon bricks are mostly used in ladle slag refining lines. Magnesia carbon bricks are easy to oxidize and are greatly affected by the oxidation of the slag. The stronger the oxidizing property of the slag, the easier it is to oxidize and corrode magnesia carbon bricks.

The oxidation of ladle slag is mainly caused by the following operating conditions.

1) The slag in the steelmaking furnace is a highly oxidizing slag containing more than 20% iron oxide. When tapping steel from the steelmaking furnace to the ladle, if the slag is not properly blocked, part of the steelmaking slag will enter the ladle, which will not only affect refining, consume more deoxidizer, but also accelerate the erosion of the ladle lining. Therefore, during the steelmaking and tapping process, slag-free technology should be adopted, that is, good slag-blocking and tapping technology will significantly reduce the erosion of the ladle lining and reduce the amount of deoxidizer.

2) For VOD and AOD furnaces, oxygen blowing decarburization is required, so the iron oxide in the slag is very high. The oxygen in the slag and the oxygen in the molten steel diffuse mutually to form a dynamic equilibrium. This also reflects the oxidation of molten steel.

High oxidation produces the following effects:

` The increase in iron oxide in the slag causes the slag viscosity and melting temperature to decrease, thus accelerating the erosion of the lining;

aAn important reaction for carbon-containing refractory materials is the oxidation of carbon. That is [{C} {O}=CO2‘, {C} [O] CO2‘]. This causes decarburization of the lining and the formation of a loose-structured decarburization layer, which causes the lining to be penetrated and eroded by slag, and also accelerates erosion. The erosion of refractory materials by oxidizing slag is very serious.

3) Use deoxidizers and detergents to deoxidize and desulfurize the molten steel in the ladle, causing the slag on the upper surface of the ladle to show reducing properties and changes in composition. This reducing slag is less corrosive to refractory materials. Among molten steel cleaners, there are aluminum calcium slag and calcium silicate slag, which have different corrosion effects on refractory materials. Generally, alumina-calcium slag corrodes magnesia-carbon bricks slightly, but corrodes magnesia-calcium carbon bricks severely. The calcium silicon slag is affected by the calcium to silicon ratio shown in Figure 1. The increase of magnesium oxide in the slag causes the unsaturation and concentration difference of magnesium oxide in the refractory material to decrease, so the driving force for dissolution decreases and the corrosion rate slows down. That is, dolomite or magnesia slag-forming agent can effectively reduce the erosion of the lining and increase the service life.

3.3. Influence of slag viscosity

The decrease in slag viscosity will cause the diffusion layer to become thinner. Because the erosion rate is inversely proportional to the diffusion layer, the reduction in slag viscosity will accelerate the erosion rate.

On the other hand, the relationship formula between slag viscosity and slag penetration depth into refractory materials shows that the slag penetration depth into refractory materials is inversely proportional to the square root of slag viscosity. Therefore, the slag viscosity decreases, resulting in an increase in the diffusion depth, that is, the slag viscosity decreases, which will thicken the reaction deterioration layer of the refractory material, leading to increased erosion. The refractory material layer penetrated by slag decreases in refractory degree, increases in sintering density, and increases in thermal expansion and other performance differences with the original layer of refractory material. During the intermittent use of the ladle, cracks and spalling of the slag penetration layer were caused, resulting in the loss of the refractory lining. Therefore, increasing the viscosity of the slag can reduce the erosion of the refractory lining and increase the service life of the ladle. The viscosity of the slag can be controlled by adding an appropriate amount of dolomite and selecting a reasonable slag-forming agent, thereby reducing the corrosion of refractory materials and extending the service life of the ladle.

4. Effect of vacuum treatment

Many refining equipment have vacuum processing functions, such as LF-VD, VOD, RH and DH, etc. Vacuum conditions have a great impact on the loss of refractory materials, especially carbon-containing refractory materials. According to the principle of chemical equilibrium, under vacuum conditions, the following reactions will be promoted to the right, causing internal vaporization of the refractory material. As a result, the carbon-containing refractory materials are internally loose, their strength is reduced, and they are even pulverized, causing the service life of the lining to decrease linearly with the extension of the VD ratio and processing time. Therefore, under high temperature vacuum conditions, it is not advisable to choose additives such as aluminum powder, silicon powder and boron carbide that are prone to redox reactions with magnesium oxide. Not only do they fail to increase the service life of the ladle, but they reduce it. CaO is not prone to redox reactions with carbon, so under certain conditions, MgO-CaO-C is more suitable for these special conditions than magnesium carbon.

5. Effect of ultra-high temperature

Ultra-high temperatures are required during the smelting process of stainless steel, that is, high temperatures above 1700°C often occur in AOD and VOD refining furnaces. The increase in temperature significantly increases the erosion rate of refractory materials, so ultra-high temperatures will cause severe erosion of refractory materials. Ultra-high temperature not only reduces the viscosity and increases the solubility of the slag, resulting in accelerated corrosion, but is also serious for carbon-containing refractory materials. According to the principle of chemical equilibrium, increasing the temperature causes the reaction to proceed to the right, which results in the same consequences as vacuum conditions. That is to say, at ultra-high temperatures, magnesia carbon brick lining containing additives such as aluminum powder and silicon powder will not have good use effect, or even worse. Therefore, during the use of refining ladles, the ultra-high temperature and the time at high temperature should be controlled.

Key Factors Impacting ladle refractory materials Lifespan
6. Effect of argon blowing and stirring

During the ladle refining process, argon is generally blown and stirred, which causes the diffusion layer at the interface between the slag and the refractory material to become thinner, so the diffusion of the erosion medium accelerates, that is, the erosion rate becomes faster. If the sample is eroded by rotation in the slag, the erosion speed of the sample is proportional to the 0.7th power of the rotation speed (J=A Bn0.7). However, argon blowing causes the oxygen concentration on the surface of the ladle slag to decrease, and argon itself is not corrosive to the furnace lining, so argon blowing can reduce the oxidation of carbon-containing refractory materials. Therefore, the impact of argon blowing on the ladle on the erosion of the refractory material of the ladle lining is not very serious.

7. Effect of intermittent operation

The ladle is in the alternating process of filling steel – transporting – refining – staying – pouring steel – turning over slag – repairing – waiting (preheating). The temperature of the ladle can continuously change from room temperature to 1700°C. This temperature fluctuation can cause significant stresses in the refractory lining. Refractory materials are brittle materials at low temperatures. Under such temperature fluctuation conditions, they are prone to cracks and peeling, resulting in abnormal losses and reducing the service life of the lining. Therefore, in order to reduce spalling and abnormal loss, the ladle turnover should be accelerated and the ladle preheating and insulation should be strengthened to prevent the temperature drop of the ladle while waiting for steel connection. This can increase the life of the ladle by more than 30%.

8. Influence of different refining equipment

Different refining equipment handles molten steel differently, that is, the refining conditions are different, and the erosion of the ladle lining is also different.

The magnesia carbon bricks used in the slag line of ordinary ladles can have a one-time service life of up to 120 times. The general LF furnace adds operating processes of argon blowing, deoxidizer, synthetic slag and arc heating. The molten steel filling time has also increased from about 60 minutes for ordinary pouring ladles to about 100 minutes. In this way, the one-time service life of the 100% LF furnace lining slag line is about 60 times, and the erosion rate has doubled, that is, the service life has been reduced by 50%. If the ladle LF treatment ratio is R1, the one-time service life of the magnesia carbon brick ladle slag line is S=120-60R1.

At present, many steel mills use LF-VD, which adds vacuum treatment to the LF treatment, resulting in a decrease in service life of about 50%. The service life of 100% VD treated LF furnace lining is half of that of pure LF furnace, about 30 heats. As the VD ratio increases, the service life decreases linearly, that is, the relationship between the service life (S2) and the VD ratio (R2) of LF-VD is approximately S2=60-30R2.

Another refining equipment, VOD, blows oxygen into the ladle to warm and decarburize the molten steel, and at the same time, a desulfurizer is added for desulfurization and vacuum degassing. The composition of the slag changes greatly, the alkalinity of the slag changes from acidic to alkaline, and the slag also changes from strong oxidizing to reducing. Its operating conditions are even worse than those of LF-VD, which results in the one-time service life of the ladle lining being further reduced by about 50%, that is, the one-time service life is about 15 times. If mixed with LF-VD, the VOD ratio is R3, then the relationship between the service life (S3) of this VOD furnace and the VOD ratio (R3) is approximately S3=30-15R3. If mixed with LF, the one-time service life is about S3=60-45R3.

It is worth pointing out that 120 times, 60 times, 30 times, and 15 times change with the maintenance of the ladle, the design of the lining, the quality of the refractory material, and the residual thickness. The above numbers are currently relatively good or normal results.

To sum up, due to the different refining conditions of ordinary ladle, LF, LF-VD and VOD, the difference in erosion speed is: ladle: LF: LF-VD: VODH1:2:4:8. Or the difference in service life is: ladle: LF: LF-VD: VOD=(100^130): (50^70): (20^30): (12^20)H8:4:2:1. That is, the unit consumption of refractory materials is 2.5, 5, 10 and 20kg/t.

The above-mentioned difference in erosion rate is reflected in key parts such as slag lines, which only account for a very small part of the lining. If a small amount of repair material is used for repair and maintenance, the service life will be increased and the unit consumption of refractory materials will be greatly reduced. Therefore, the non-uniformity of metallurgical lining erosion brings a lot of room for reducing the unit consumption of refractory materials.

1.The increase in ladle temperature significantly increases the erosion rate of refractory materials; the ladle lining corrosion increases with the prolongation of refining time.

2.Slag is the main medium that corrodes the ladle lining. The enhanced oxidation of slag and the reduced viscosity and alkalinity all lead to accelerated corrosion of refractory materials.

3.Ultra-high temperature and vacuum treatment of the ladle not only lead to accelerated melting corrosion, but also cause the oxidation-reduction reaction of internal gasification of carbon-containing refractory materials to occur, thereby making the erosion and loss of refractory materials more rapid.

4.Under long-term vacuum treatment and ultra-high temperature smelting conditions, carbon-containing refractory materials are not suitable. Carbon-containing refractory materials containing traditional additives have worse use effects.

5.Argon blowing does not significantly increase the erosion of the lining, while oxygen blowing greatly accelerates the erosion of the refractory material.

6.Different refining equipment has different effects on refractory material erosion. The difference in erosion speed of different refining equipment is: ladle: LF: LF-VD: VODH1:2:4:8. The service life of the lining decreases linearly with the refining ratio.

Through good slag blocking and tapping technology and controlling the oxidation of slag, controlling the viscosity, alkalinity and composition of the slag by controlling the addition of synthetic slag is a very effective method to reduce the corrosion of refractory materials.

Appropriately lowering the steelmaking temperature and preventing the steelmaking temperature from being too high is one of the effective methods to increase the service life of the ladle.

Smooth operation is an effective way to reduce localized overheating and severe erosion.

Rapid turnaround and ladle insulation to reduce temperature fluctuations can significantly increase ladle life.
Choose HYFR, Choose the top quality of China!
Choose HYRE, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!

Oznake: ladle shroud, slide gate plate, tundish stopper

Key Factors Impacting ladle refractory materials Lifespan

Refractory materials for ladles account for more than 30% of iron and steel metallurgical refractory materials and are the focus of metallurgical refractory material consumption. At present, ordinary small ladles use aluminum-magnesia castables with high aluminum as the main raw material. The service life has reached more than 70 times, and the good ones have reached more than 150 times. Especially when the cold repair mode of cold peeling and then casting restoration is adopted, And repeat.

For medium and large ladles, magnesia-carbon bricks are generally used for the slag line, and corundum-spinel or alumina-magnesia castables or alumina-magnesia carbon bricks are used for other parts. And 2 or 3 slag lines and bottom bricks are balanced with 1 molten pool lining, so that the unit consumption of refractory materials is 2~4kg/t. However, there are also low-grade brick-built ladles with low service life, no repairs, and one-time replacement, resulting in high unit consumption of refractory materials.

As the quality of steel products improves, an increasing proportion of processes such as argon blowing and stirring, oxygen blowing to decarburize, heating, slag addition, alloying elements, and vacuum are required to be carried out in the ladle. These processes lead to longer and longer residence times of molten steel in the ladle, accelerated erosion of the refractory lining and a significant reduction in service life.

This study analyzes and discusses the impact of each refining process parameter on the lining, revealing their influence rules. These rules are used to combine the operating conditions with improving the service life of the ladle to achieve the purpose of increasing the service life of the ladle and reducing the unit consumption of refractory materials.

Effect of usage conditions on corrosion of lining refractory materials

1. Effect of temperature

The relationship between the dissolution rate of the ladle lining refractory material and temperature. When the temperature of the molten steel in the ladle is higher, the dissolution and erosion will be faster and the service life will be shorter. Researchers conducted a systematic study on the resistance of refining ladle materials to slag dissolution and obtained very instructive conclusions.

The increase in the temperature of the molten steel in the ladle significantly increases the erosion rate. An important process of ladle refining is that the input of heat energy such as arc heating, electromagnetic stirring heating, adding exothermic agent or oxygen blowing increases the temperature of the ladle, resulting in accelerated erosion of the ladle lining and reduced service life. This is one of the important reasons why the service life of refining equipment such as VOD and LF is significantly lower than that of ordinary ladles.

On the other hand, temperature uniformity is also an important factor affecting the service life and safety of refining ladles. For the LF furnace, arc heating leads to local hot spots and accelerated damage. Without repair, the fastest erosion determines the service life, thus leading to a reduction in the service life of the ladle. In this case, reducing the continuous heating time and appropriately reducing the heating intensity is very effective in reducing hot spot overheating and increasing the service life of the ladle lining. In addition, timely repairs and balanced ladle lining are required.

2. Influence of filling time of molten steel

Under normal circumstances, molten steel hardly dissolves refractory materials, or molten steel dissolves refractory materials very slowly. The corrosion of refractory materials in ladles is mainly caused by slag.

The effect of molten steel on refractory materials is mainly reflected in three aspects:

First, during the processes of tapping, pouring, and argon blowing and stirring, the flow rate and impact force of the molten steel are very large, eroding the refractory lining, resulting in refractory material loss and refractory particles entering the molten steel. Most of the refractory particles entering the molten steel float to the slag, while a small number of tiny particles cannot float and form non-metallic inclusions in the steel, which affects the quality of the steel.

The second is that the lining refractory material dissolves into the molten steel. Generally, the solubility of refractory materials in steel is very low, and there is little dissolution and erosion. However, some components (such as carbon) in refractory materials have high solubility in steel and dissolve into steel, which affects the production of low carbon steel and ultra-low carbon steel.

Third, certain components of the refractory material interact with certain components in the molten steel (especially some special steel components), causing chemical reactions, resulting in changes in the steel composition and erosion of the refractory material.

The residence time of molten steel in the ladle is divided into tapping time (2 to 7 minutes), refining time, residence time and steel pouring time. The degree of erosion of the refractory lining during these periods is different. During the tapping process, the impact of the molten steel on the lining causes local erosion loss. At the same time, the strong stirring causes the reaction corrosion between the slag and the refractory material to be intense. During the refining process, the longer the refining time, the more the slag reacts with the refractory material, and the greater the corrosion amount, that is, the lower the service life of the ladle. The service life of the ladle lining decreases linearly with the extension of the refining time. During the residence period, as the time prolongs, the interface reaction layer thickens, and the reactants and products need to diffuse for a long time. The erosion is controlled by diffusion.

According to the diffusion kinetic equation, the amount of erosion is proportional to the square root of the residence time. Therefore, the lining refractory material erodes slowly during the residence period. During the steel pouring process, slag rises up and falls through different positions of the ladle, which is the main cause of erosion of the ladle molten pool. However, during the steel pouring process, the contact time between the slag and the lining somewhere is very short, so the erosion of the lining during the steel pouring process is still very small.

2. Influence of filling time of molten steel

Under normal circumstances, molten steel hardly dissolves refractory materials, or molten steel dissolves refractory materials very slowly. The corrosion of refractory materials in ladles is mainly caused by slag.

The effect of molten steel on refractory materials is mainly reflected in three aspects:

First, during the processes of tapping, pouring, and argon blowing and stirring, the flow rate and impact force of the molten steel are very large, eroding the refractory lining, resulting in refractory material loss and refractory particles entering the molten steel. Most of the refractory particles entering the molten steel float to the slag, while a small number of tiny particles cannot float and form non-metallic inclusions in the steel, which affects the quality of the steel.

The second is that the lining refractory material dissolves into the molten steel. Generally, the solubility of refractory materials in steel is very low, and there is little dissolution and erosion. However, some components (such as carbon) in refractory materials have high solubility in steel and dissolve into steel, which affects the production of low carbon steel and ultra-low carbon steel.

Third, certain components of the refractory material interact with certain components in the molten steel (especially some special steel components), causing chemical reactions, resulting in changes in the steel composition and erosion of the refractory material.

The residence time of molten steel in the ladle is divided into tapping time (2 to 7 minutes), refining time, residence time and steel pouring time. The degree of erosion of the refractory lining during these periods is different. During the tapping process, the impact of the molten steel on the lining causes local erosion loss. At the same time, the strong stirring causes the reaction corrosion between the slag and the refractory material to be intense. During the refining process, the longer the refining time, the more the slag reacts with the refractory material, and the greater the corrosion amount, that is, the lower the service life of the ladle. The service life of the ladle lining decreases linearly with the extension of the refining time. During the residence period, as the time prolongs, the interface reaction layer thickens, and the reactants and products need to diffuse for a long time. The erosion is controlled by diffusion.

According to the diffusion kinetic equation, the amount of erosion is proportional to the square root of the residence time. Therefore, the lining refractory material erodes slowly during the residence period. During the steel pouring process, slag rises up and falls through different positions of the ladle, which is the main cause of erosion of the ladle molten pool. However, during the steel pouring process, the contact time between the slag and the lining somewhere is very short, so the erosion of the lining during the steel pouring process is still very small.

Key Factors Impacting ladle refractory materials Lifespan
3.2. Influence of slag oxidation

At present, magnesia carbon bricks are mostly used in ladle slag refining lines. Magnesia carbon bricks are easy to oxidize and are greatly affected by the oxidation of the slag. The stronger the oxidizing property of the slag, the easier it is to oxidize and corrode magnesia carbon bricks.

The oxidation of ladle slag is mainly caused by the following operating conditions.

1) The slag in the steelmaking furnace is a highly oxidizing slag containing more than 20% iron oxide. When tapping steel from the steelmaking furnace to the ladle, if the slag is not properly blocked, part of the steelmaking slag will enter the ladle, which will not only affect refining, consume more deoxidizer, but also accelerate the erosion of the ladle lining. Therefore, during the steelmaking and tapping process, slag-free technology should be adopted, that is, good slag-blocking and tapping technology will significantly reduce the erosion of the ladle lining and reduce the amount of deoxidizer.

2) For VOD and AOD furnaces, oxygen blowing decarburization is required, so the iron oxide in the slag is very high. The oxygen in the slag and the oxygen in the molten steel diffuse mutually to form a dynamic equilibrium. This also reflects the oxidation of molten steel.

High oxidation produces the following effects:

` The increase in iron oxide in the slag causes the slag viscosity and melting temperature to decrease, thus accelerating the erosion of the lining;

aAn important reaction for carbon-containing refractory materials is the oxidation of carbon. That is [{C}+{O}=CO2‘, {C}+[O]+CO2‘]. This causes decarburization of the lining and the formation of a loose-structured decarburization layer, which causes the lining to be penetrated and eroded by slag, and also accelerates erosion. The erosion of refractory materials by oxidizing slag is very serious.

3) Use deoxidizers and detergents to deoxidize and desulfurize the molten steel in the ladle, causing the slag on the upper surface of the ladle to show reducing properties and changes in composition. This reducing slag is less corrosive to refractory materials. Among molten steel cleaners, there are aluminum calcium slag and calcium silicate slag, which have different corrosion effects on refractory materials. Generally, alumina-calcium slag corrodes magnesia-carbon bricks slightly, but corrodes magnesia-calcium carbon bricks severely. The calcium silicon slag is affected by the calcium to silicon ratio shown in Figure 1. The increase of magnesium oxide in the slag causes the unsaturation and concentration difference of magnesium oxide in the refractory material to decrease, so the driving force for dissolution decreases and the corrosion rate slows down. That is, dolomite or magnesia slag-forming agent can effectively reduce the erosion of the lining and increase the service life.

3.3. Influence of slag viscosity

The decrease in slag viscosity will cause the diffusion layer to become thinner. Because the erosion rate is inversely proportional to the diffusion layer, the reduction in slag viscosity will accelerate the erosion rate.

On the other hand, the relationship formula between slag viscosity and slag penetration depth into refractory materials shows that the slag penetration depth into refractory materials is inversely proportional to the square root of slag viscosity. Therefore, the slag viscosity decreases, resulting in an increase in the diffusion depth, that is, the slag viscosity decreases, which will thicken the reaction deterioration layer of the refractory material, leading to increased erosion. The refractory material layer penetrated by slag decreases in refractory degree, increases in sintering density, and increases in thermal expansion and other performance differences with the original layer of refractory material. During the intermittent use of the ladle, cracks and spalling of the slag penetration layer were caused, resulting in the loss of the refractory lining. Therefore, increasing the viscosity of the slag can reduce the erosion of the refractory lining and increase the service life of the ladle. The viscosity of the slag can be controlled by adding an appropriate amount of dolomite and selecting a reasonable slag-forming agent, thereby reducing the corrosion of refractory materials and extending the service life of the ladle.

4. Effect of vacuum treatment

Many refining equipment have vacuum processing functions, such as LF-VD, VOD, RH and DH, etc. Vacuum conditions have a great impact on the loss of refractory materials, especially carbon-containing refractory materials. According to the principle of chemical equilibrium, under vacuum conditions, the following reactions will be promoted to the right, causing internal vaporization of the refractory material. As a result, the carbon-containing refractory materials are internally loose, their strength is reduced, and they are even pulverized, causing the service life of the lining to decrease linearly with the extension of the VD ratio and processing time. Therefore, under high temperature vacuum conditions, it is not advisable to choose additives such as aluminum powder, silicon powder and boron carbide that are prone to redox reactions with magnesium oxide. Not only do they fail to increase the service life of the ladle, but they reduce it. CaO is not prone to redox reactions with carbon, so under certain conditions, MgO-CaO-C is more suitable for these special conditions than magnesium carbon.

5. Effect of ultra-high temperature

Ultra-high temperatures are required during the smelting process of stainless steel, that is, high temperatures above 1700°C often occur in AOD and VOD refining furnaces. The increase in temperature significantly increases the erosion rate of refractory materials, so ultra-high temperatures will cause severe erosion of refractory materials. Ultra-high temperature not only reduces the viscosity and increases the solubility of the slag, resulting in accelerated corrosion, but is also serious for carbon-containing refractory materials. According to the principle of chemical equilibrium, increasing the temperature causes the reaction to proceed to the right, which results in the same consequences as vacuum conditions. That is to say, at ultra-high temperatures, magnesia carbon brick lining containing additives such as aluminum powder and silicon powder will not have good use effect, or even worse. Therefore, during the use of refining ladles, the ultra-high temperature and the time at high temperature should be controlled.

Key Factors Impacting ladle refractory materials Lifespan
6. Effect of argon blowing and stirring

During the ladle refining process, argon is generally blown and stirred, which causes the diffusion layer at the interface between the slag and the refractory material to become thinner, so the diffusion of the erosion medium accelerates, that is, the erosion rate becomes faster. If the sample is eroded by rotation in the slag, the erosion speed of the sample is proportional to the 0.7th power of the rotation speed (J=A+Bn0.7). However, argon blowing causes the oxygen concentration on the surface of the ladle slag to decrease, and argon itself is not corrosive to the furnace lining, so argon blowing can reduce the oxidation of carbon-containing refractory materials. Therefore, the impact of argon blowing on the ladle on the erosion of the refractory material of the ladle lining is not very serious.

7. Effect of intermittent operation

The ladle is in the alternating process of filling steel – transporting – refining – staying – pouring steel – turning over slag – repairing – waiting (preheating). The temperature of the ladle can continuously change from room temperature to 1700°C. This temperature fluctuation can cause significant stresses in the refractory lining. Refractory materials are brittle materials at low temperatures. Under such temperature fluctuation conditions, they are prone to cracks and peeling, resulting in abnormal losses and reducing the service life of the lining. Therefore, in order to reduce spalling and abnormal loss, the ladle turnover should be accelerated and the ladle preheating and insulation should be strengthened to prevent the temperature drop of the ladle while waiting for steel connection. This can increase the life of the ladle by more than 30%.

8. Influence of different refining equipment

Different refining equipment handles molten steel differently, that is, the refining conditions are different, and the erosion of the ladle lining is also different.

The magnesia carbon bricks used in the slag line of ordinary ladles can have a one-time service life of up to 120 times. The general LF furnace adds operating processes of argon blowing, deoxidizer, synthetic slag and arc heating. The molten steel filling time has also increased from about 60 minutes for ordinary pouring ladles to about 100 minutes. In this way, the one-time service life of the 100% LF furnace lining slag line is about 60 times, and the erosion rate has doubled, that is, the service life has been reduced by 50%. If the ladle LF treatment ratio is R1, the one-time service life of the magnesia carbon brick ladle slag line is S=120-60R1.

At present, many steel mills use LF-VD, which adds vacuum treatment to the LF treatment, resulting in a decrease in service life of about 50%. The service life of 100% VD treated LF furnace lining is half of that of pure LF furnace, about 30 heats. As the VD ratio increases, the service life decreases linearly, that is, the relationship between the service life (S2) and the VD ratio (R2) of LF-VD is approximately S2=60-30R2.

Another refining equipment, VOD, blows oxygen into the ladle to warm and decarburize the molten steel, and at the same time, a desulfurizer is added for desulfurization and vacuum degassing. The composition of the slag changes greatly, the alkalinity of the slag changes from acidic to alkaline, and the slag also changes from strong oxidizing to reducing. Its operating conditions are even worse than those of LF-VD, which results in the one-time service life of the ladle lining being further reduced by about 50%, that is, the one-time service life is about 15 times. If mixed with LF-VD, the VOD ratio is R3, then the relationship between the service life (S3) of this VOD furnace and the VOD ratio (R3) is approximately S3=30-15R3. If mixed with LF, the one-time service life is about S3=60-45R3.

It is worth pointing out that 120 times, 60 times, 30 times, and 15 times change with the maintenance of the ladle, the design of the lining, the quality of the refractory material, and the residual thickness. The above numbers are currently relatively good or normal results.

To sum up, due to the different refining conditions of ordinary ladle, LF, LF-VD and VOD, the difference in erosion speed is: ladle: LF: LF-VD: VODH1:2:4:8. Or the difference in service life is: ladle: LF: LF-VD: VOD=(100^130): (50^70): (20^30): (12^20)H8:4:2:1. That is, the unit consumption of refractory materials is 2.5, 5, 10 and 20kg/t.

The above-mentioned difference in erosion rate is reflected in key parts such as slag lines, which only account for a very small part of the lining. If a small amount of repair material is used for repair and maintenance, the service life will be increased and the unit consumption of refractory materials will be greatly reduced. Therefore, the non-uniformity of metallurgical lining erosion brings a lot of room for reducing the unit consumption of refractory materials.

1.The increase in ladle temperature significantly increases the erosion rate of refractory materials; the ladle lining corrosion increases with the prolongation of refining time.

2.Slag is the main medium that corrodes the ladle lining. The enhanced oxidation of slag and the reduced viscosity and alkalinity all lead to accelerated corrosion of refractory materials.

3.Ultra-high temperature and vacuum treatment of the ladle not only lead to accelerated melting corrosion, but also cause the oxidation-reduction reaction of internal gasification of carbon-containing refractory materials to occur, thereby making the erosion and loss of refractory materials more rapid.

4.Under long-term vacuum treatment and ultra-high temperature smelting conditions, carbon-containing refractory materials are not suitable. Carbon-containing refractory materials containing traditional additives have worse use effects.

5.Argon blowing does not significantly increase the erosion of the lining, while oxygen blowing greatly accelerates the erosion of the refractory material.

6.Different refining equipment has different effects on refractory material erosion. The difference in erosion speed of different refining equipment is: ladle: LF: LF-VD: VODH1:2:4:8. The service life of the lining decreases linearly with the refining ratio.

Through good slag blocking and tapping technology and controlling the oxidation of slag, controlling the viscosity, alkalinity and composition of the slag by controlling the addition of synthetic slag is a very effective method to reduce the corrosion of refractory materials.

Appropriately lowering the steelmaking temperature and preventing the steelmaking temperature from being too high is one of the effective methods to increase the service life of the ladle.

Smooth operation is an effective way to reduce localized overheating and severe erosion.

Rapid turnaround and ladle insulation to reduce temperature fluctuations can significantly increase ladle life.
Choose HYFR, Choose the top quality of China!
Choose HYRE, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!

Oznake: ladle shroud, slide gate plate, tundish stopper

Causes of damage to ladle porous plug bricks

Heat stress
In actual production, the ladle temperature reaches more than 1000, and the molten steel temperature reaches more than 1600. The temperature difference between the two when in contact will produce large thermal stress, which in turn causes a very large thermal shock.

The ladle is in a repetitive working environment. The thermal stress caused by the frequent temperature changes of the air brick when it contacts the molten steel and the ladle is one of the reasons for the damage of the air brick. The key factor for the thermal stress of the air brick is the change of temperature, and the temperature changes of different parts of the air brick are different.

The difference between the thermal stress generated by the internal parts of the air brick and the temperature change at the same position is compared. It is found that the thermal stress near the working surface exceeds the bonding strength of the air brick itself to a certain extent. The air brick is subjected to a strong thermal shock, resulting in layered peeling of the working surface of the air brick, which leads to the destruction of the air brick.

The temperature field formed at the bottom of the ladle when the molten steel enters and exits the ladle and the stress field generated by the molten steel are numerically simulated and analyzed, and numerical detection is performed.

The study found that, if the ladle is to reach a “quasi-steady state”, the preheated ladle needs to be subjected to several thermal cycles. Since the stress of the working layer near the ladle wall at the bottom of the ladle is higher than that near the center, in order to reduce the thermal stress generated there, an insulation device can be added near the ladle wall to alleviate this phenomenon.

Causes of damage to ladle porous plug bricks
Mechanical wear
There are roughly three situations in which turbulence scours the Ladle porous plug bricks.

When the air bricks are higher than the seat bricks, the main reason for the damage to the air bricks is that the molten steel in the ladle forms a vortex that produces a huge shear effect and scouring effect on the side of the air bricks. Therefore, the scouring force is one of the reasons for the great damage to the seat bricks of the air bricks. In a normal working environment, the air seat bricks are used only once, and the structure above the seat bricks will be washed away after one time;
When the air bricks are level with the seat bricks, the seat bricks protect the air bricks from erosion and damage. The vortex formed by the molten steel first scours the seat bricks, causing the shear force of the air bricks to decrease accordingly;
When the air bricks are lower than the seat bricks, cold steel is easily accumulated on the working surface during normal work. Since the viscosity of the remaining cold steel is relatively large, it has a certain obstruction to the blowing, so the blowing pressure needs to be increased to meet the refining requirements. In this way, the scouring force of the air flow on the air bricks is correspondingly increased, and the shear and impact strength is large, making them more easily damaged. In order to meet the requirements of off-furnace refining for blow-through rate and service life, the air-permeable brick must have excellent anti-scouring ability and high-temperature mechanical properties.
When there are differences in refining conditions, the aggregate and matrix are properly proportioned to reduce the impact of erosion and penetration on the blow-through rate and service life of the air-permeable brick.

Mechanical stress
During use, the working surface of the air bricks at the bottom of the ladle is in direct contact with the high-temperature molten steel. Under the condition of cyclic use, the temperature in the ladle is always in a state of change.

For example, when the refractory material at the bottom of the ladle is used, a temperature difference will occur from high temperature to low temperature. Since the expansion coefficient of the original layer of the refractory material is different from that of the metamorphic layer, the air bricks are subjected to shear stress, resulting in transverse cracks or even fractures in the air brick structure.

Chemical attack
The working layer of the air brick is in contact with the steel slag and molten steel for a long time, and the molten slag continuously erodes and penetrates into the air brick. The oxides such as MnO, MgO, SiO2, FeO, Fe2O3 in the molten steel and slag react with the refractory materials in the air brick.

The physical erosion caused by the melting and peeling of the working layer of the air brick by molten steel, and the chemical erosion caused by the continuous penetration of slag and molten steel into the air brick during the smelting process are the two main reasons for the damage of the air brick. Therefore, in order to improve the thermal shock resistance and slag resistance of the material, it is necessary to improve the toughness and permeability of the air brick.
Choose HYFR, Choose the top quality of China!
Choose HYRE, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!

Oznake: ladle shroud, slide gate plate, refractory

Installation Process & Best Practices for Tundish Linings

Key Requirements for Magnesia-Based Dry Vibratable Materials
Material Composition and Temperature Guidelines
Magnesita refractories utilize a hybrid binder system combining organic and inorganic agents. To preserve binding integrity during installation:

Permanent layer temperature must stay below 100°C (lower preferred)
Working layer thickness: 40-50mm for bottom, 45-60mm for walls (55mm minimum at slag line)
Minimum operational lifespan: 12 hours under continuous casting conditions
Step-by-Step Installation Process
Preparation and Base Layer Formation
When using magnesita refractories:

Install impact pads and nozzle blocks with compacted ramming mix
Spread dry material evenly across tundish bottom (40-50mm)
Position and align forming mold with 45-60mm clearance from permanent walls
Vibration Process and Curing Protocol
Advanced vibration techniques ensure optimal density:

Layer-by-layer filling with 3-5min vibration cycles
Low-temperature curing at 200-250°C for 60-90 minutes
Controlled cooling to below 100°C before demolding
Post-Installation Procedures
Quality Inspection and Final Assembly
After demolding magnesia-based linings:

Check for surface defects (cracks e2mm require repair)
Install flow control components with precision alignment
Backfill joints with matching dry vibratable material
Optimized Baking Curve for Magnesita Refractories
Thermal Treatment Guidelines
Proper baking ensures maximum performance:

Initial phase: d800°C for 30 minutes (ramp rate: 15°C/min)
Final phase: 1100°C peak (minimum 70 minutes dwell)
Total bake time: 70-180 minutes (avoid over-firing)
Carbon Preservation Strategies
To maintain erosion resistance in magnesita refractories:

Limit total thermal exposure time
Use controlled atmosphere during baking
Monitor organic binder degradation points
Why Choose Magnesita Refractories?
Performance Advantages
15-20% longer campaign life vs conventional materials
Reduced breakout risk through precise thermal expansion control
Lower inclusion rates in final steel product
Maintenance Best Practices
Extend service life of magnesia-based linings:

Implement post-casting inspection routines
Use laser profiling for wear measurement
Schedule preventive repairs at 8-10 hour intervals
Choose HYFR, Choose the top quality of China!
Choose HYRE, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!
Choose HYFR, Choose the top quality of China!

10 Advantages of Lithium Polymer Battery for Common Users

Lithium polymer batteries have the same technology that is used by liquid lithium ion batteries. In other words, the anode and cathode are of the same type. The only difference is that these units use aluminum plastic film and gel electrolytes. Therefore, these power packs are thinner and lighter but offer a higher density of energy. In this article, we are going to talk about 10 advantages of these power packs. Read on to find out more.

1. High Energy Density

Compared to nickel-hydride or nickel-cadmium, lithium-polymer batteries are 50% lighter. But they have the same degree of energy density, which makes them an ideal choice.

2. Thin Design

Liquid lithium-ion battery features a customized shell and positive/negative electrodes. And then there is a technical limit that doesn't allow the batteries to be thinner than 3.6mm. On the other hand, the polymer cells don't have any such limitations. Therefore, the thickness of these units can below 1mm.

3. Low Internal Resistance

Unlike liquid batteries, the polymer type has less internal resistance. Therefore, these batteries can help extend the time your applications can stay on standby mode. So, this is another great advantage of these units.

4. Customizable Shape

Based on demand, polymer batteries can be made thicker or thinner. For instance, for special smartphones, manufacturers may require thinner batteries. This can help get the most out of the available space and still enjoy long backup.

5. Good Charge/Discharge Rate

If you use the right type of charger, you can recharge these units in just two hours. Basically, polymer batteries make use of colloidal electrolytes that have a stable discharge rate, unlike liquid electrolytes.

6. High Voltage

A lithium-polymer cell has an operating voltage of 3.7v on average, which is equal to three nickel-hydride or nickel-cadmium ones connected in series.

7. High Safety and Performance

The outer shell of these batteries is made of aluminum plastic. On the other hand, liquid lithium ones come with a metal shell. Because of the flexible packaging, the deformation of the outer shell won't cause the battery to stop working.

8. Long Cycle Life

In normal circumstances, a lithium polymer battery tends to charge and discharge more than 500 times. Therefore, you can enjoy long cycle life if you opt for these powerhouses.

9. No Pollution

Also, lithium-polymer units don't contain harmful metals like mercury, lead, or cadmium. Therefore, they don't cause pollution unlike other types of units.

10. No Memory Effect

Nickel-cadmium batteries tend to lose their discharge with the passage of time. On the other hand, lithium-polymer ones have no such problem. This is also called the memory effect. With time, the market share of these power packs is rising because of the list of advantages these batteries offer.

Also, these batteries are used in power tools and laptops as well. Therefore, these are becoming quite popular as time goes by.

Long story short, these are just 10 of the most common advantages of Lithium polymer battery packs. Hopefully, this article will help you get a deeper insight into these units.

Are you looking for a Custom Li-Polymer Battery? If so, we suggest that you try out a great collection of these units at https://www.ludabattery.com/.

Oznake: lipo battery

Lipo Battery Pack Tutorial

So you want to go lipo?

Well you have made the big choice and now you need to know where to start. Well, the first thing to look at is the condition on your gearbox. This is going to be one of those times where you have to be very truthful with yourself. Is this gearbox in the best shape it can be? When was the last time you shimmed the gearbox? When did you last grease the gearbox? If you have not taken the time to make sure you have no noise or play in your gears take that time now. You will pay later when a subtle oscillation turns into a spinning gear of death and takes out your AEG in the middle of sustained fire if you don't.

While you are in the gearbox there are some other things you should look at. What gauge and quality is your wiring? If you are not at 16 or 18 gauge wire then take the time now and change it so that you have a big enough and strong enough pipe to push the new sustained voltage.

The C rating of a lithium polymer battery denotes how much current you can draw out of a pack at a continuous rate. Example:

1600mah 10c battery 1600mah/10000mah = 1.6ah 1.6ah x 10c = 16 amps

1000mah 20C Pack 1000mah/1000mah = 1ah, 1ah x 20c = 20 Amps

1500mah 25C Battery 1500mah/1000mah = 1.5ah, 1.5ah x 25c = 37.5 Amps

So the higher your discharge rate (C Rating) the more amperes you can push out continuously. Resulting in your motor being able to pull as much as it wants/can for a longer time. Most NIMH batteries are 10c.

You may also want to do an AOE (angle of engagement) correction. This involves totally readjusting the timing on your piston head and should not be performed if you do not fully feel confident.

First remove the second to last tooth on the piston. Then shim the piston head so that the piston lines up exactly with the first tooth on the sector gear. We have a guide HERE. You may also want to upgrade all the other fun parts that require you to have the gearbox and gun body open.

New stronger spring

New piston

New Piston Head

New air seal nozzle

New bucking

New inner barrel

Now this is no small amount of work.

Taking apart a gearbox and replacing a spring can be a daunting challenge depending on your level of skill but with time and the wonderful world wide web you can find step-by-step guides to disassemble and reassemble your gearbox. See our guide HERE.

Then we can talk about MOSFET. MOSFET is an electrical switch that (in simple terms) regulates voltage to your gearbox. You can wire one in, but if you go for a 7.4v it is only necessary for ROF regulation, but if you are going for the 11.1 then you really should put one in. Installation and operation are part-specific and come with detailed instructions.

Now that you have a new freshly shimmed tricked-out gearbox now what? You need to look at your connectors. Deans are one of the most popular connectors because they have a lower resistance than the standard mini Tamiya, and they are a soldered connection not a crimped, that is why many people switch to them. They do require solder but with a little time and patience that should be not problem for the average person. You can see a great guide HERE.

So now it comes down to the real deal 7.4 or 11.1. If you are confident in your work switching to an 11.1 is not a big deal but this is a higher voltage and a longer sustained amperage so this is for those who want the highest rate of fire. If you are just looking for a longer play time then 7.4v should get you a rate of fire in between a 8.4 and 9.6 and with the upgraded internals any AEG will handle a 7.4v lipo.

Plus we all know about air discharge. Nickel metal hydride batteries are great if you charge them the night before but you will have to charge them every time. There will always be a little "air discharge" but with Lithium, you get nearly none.

Oznake: lipo battery

7 Tips To Maximizing Your Battery Performance

Battery technology seems to have taken a leaping step recently, allowing electric RC models to go places where once only nitrous models could go. Leading this innovation are the Li-Po or Lithium Polymer batteries which has become the standard power source for electric-powered helicopters, planes, cars, boats, and almost every other type of model. However, these batteries are not exactly cheap, and improper operations will have detrimental effects. Here are seven tips to maximize your battery performance.

1. Break In New Batteries

Although not as big a deal with newer Li-Po packs as it was when NiMh and NiCad batteries were kings, it is still recommended that you fully charge the battery before first use. Fully discharging and charging batteries a few times before the first flight or will also give your battery a little bit extra lifetime and power.

2. Keep the pack clean

This is probably one of the most overlooked aspects of battery operations. It is a good idea to keep the battery pack clean, and this is especially important for the dean connectors. If the dean connectors are dirty, the connection may be obstructed and could result in a mid-flight power failure. The easiest way to clean dirty contacts is simply with alcohol and cotton swabs.

3. Keep up the battery's health by constant exercise

Leaving the battery inactive for a long period of time shortens its life and decreases its total potential. You should use your battery pack at least once every one to two weeks. Fully discharging then charging the pack will also quell this problem.

4. Take breaks between flights

A fully charged lipo pack has enough power for a 10-minute flight. However, to fly for ten minutes straight on one pack is not recommended. If you have two packs, it's best to fly a 5-minute flight, switch to a fresh pack, fly for another 5 minutes, and then switch back to the old pack. Doing this will greatly increase the lifespan of the battery.

5. Do not charge when hot

Never charge the battery pack while it is still hot. The battery pack becomes very hot right after a flight; you must wait until it cools down before charging it again. Charging a still-hot pack is one of the most successful ways to shorten a battery's life.

6. Store them well

To store the battery for a prolonged period (a month or more), the best way to store them is in a clean, dry, cool place away from metal and heat. Remember also that battery packs lose charge over time even without usage.

7. Avoid hard impact

Individual cells within a battery pack can be damaged upon heavy impact which could cause circuit leaks and can be dangerously unstable. There is also no way to repair a damaged cell. Try your best not to crash, but of course, we all already do.

Oznake: Lithium-ion polymer

10 Tips to Longer Lasting Forklift Batteries

1. Check the automatic watering systems.
These systems tend to be clogged during use. They also tend to be located in the lift and not taken out very often, so they get clogged. This often goes unchecked, the clog is not discovered and the cell gets burned up and dried. This results in $400 - $600 costs for a cell change and this is a frequent issue commonly seen that could be avoided.
2. Clean the tops of the batteries of acid and corrosion.
A dirty battery causes a lot of problems. If you put a voltmeter on top there actually is a slow discharge of the battery. If you charge a battery it will slowly discharge over time. Corrosion builds up and will ruin your cables which causes poor battery performance. Cables can get expensive at $70 - $100 each if you have a lot of batteries, in addition to degrading your battery performance. This can be avoided just by taking a little time to clean the top of the batteries.
3. Keep on top of underperforming batteries.
A lot of companies don't take care of the problem batteries. Underperforming batteries can draw heavy loads on electrical components of the forklift which are very expensive to the thousands of dollars. The damage happens when the battery gets low and it is used anyway.
You can tell a battery is underperforming if it doesn't last a full shift. A lot of batteries only go for 1 or 2 hours and the drivers don't know which ones are good or bad. They just put them in and the batteries draw very quickly.
Facilities that have under performing batteries can spend thousands per month replacing electrical components in forklifts and the root cause is under performing batteries. These batteries can be identified, Brought Up To Full Performance and this expense can be saved.
When the lifts go down you have less productivity, less product moved, more battery changes, and unnecessary costs of replacing components and the labor to do so.
4. Use filtered water in batteries.
Being in so many facilities and seeing things first hand I can tell you without hesitation that using tap water in your batteries will cause you problems and unnecessary expense. I see this all the time. Batteries that use tap water are far worse than all the rest of them. They heat up more. The minerals in the water build-up on the plates and it causes heat. Heat causes premature battery failure. My estimate is you cut battery life by 50%. Even if your battery is covered by a warranty you have to ship it out and wait for it to come back, and incur the costs to do so. This can be avoided by using filtered water.
5. Use a water de-ionizer.
A cheap and effective solution to the problem of using filtered water. You can attach it to your water line, it is cheap and you get the benefits of filtered water. It's easy to use. You don't have to mess with bottles of filtered water. You can use an automatic water gun and a battery is filled up in seconds rather than the minute or so it takes to pour in filtered water from a bottle, which is probably the main deterrent to using filtered water. This makes filling up easy and painless and eliminates the minerals that pollute the batteries and cause you the expense and lost productivity.
6. Do not allow opportunity charging.
Do not allow charging during 15-minute breaks and lunch periods. Batteries are made to draw down 80% and then be full charged. If you opportunity charges you significantly reduce the life of your battery.
I think the reason this process starts is when you have underperforming batteries, the drivers know this and they try to get a little more charge during their breaks.
Opportunity charging accelerates the deterioration of battery performance. If you identify the lesser performing batteries you can avoid this issue.
This can reduce battery life by a year or two, plus you have the cost of electricity for unnecessary charging and the labor cost and lost productivity when a battery needs to be charged.
7. Do not equalize the batteries more than once a month.

Equalizing creates tremendous heat, particularly when a battery is a little older. Heat kills batteries. It sheds the lead. Equalizing can give a temporary boost but the battery is used up more quickly. I go into facilities and literally see batteries steaming from the heat.
The temporary boost you get comes at a high cost of a shorter battery life and the costs of increased handling and maintenance.

8. The batteries should cool down after charging.

Remember, heat kills batteries. If they are charged and then immediately used they are hot a lot longer. Companies that get the most from their batteries let them cool a few hours after charging.

9. Do a quick check of cables and connections monthly.
This can easily be overlooked. At a glance, everything might look all right but a closer inspection can pick up corrosion which does not allow electricity to pass through. Jiggle the cables and make sure the connections are solid.
Bad cables impact battery performance. If electricity doesn't pass though efficiently, your battery is not discharging or charging completely. You might think your battery is bad, but it really it really can't be charged completely because the cables are bad. So check them for corrosion.
10. Program your chargers with a 30-minute delay.
One company I service couldn't stop their workers from opportunity charging during breaks and lunch when they were not being watched. So, they installed a 30-minute delay on the charger.
The workers plug in as normal but they are not being charged due to the delay.
The disadvantages and costs of opportunity charging are so significant that installing a delay was a very smart move for this facility. Most of the breaks are 15 or 30 minutes and it eliminated charging during this time.
Summary
Batteries will last a lot longer. A typical warranty is 5 years but you can get 7 or 8 years of productive lift from a battery. If you are not doing the above a battery may only be productive for a year or two and then it is under performing, with all the attendant unnecessary time, labor and expense, for the last few years it is in use. You incur the consequences of increased charging, lost productivity and unnecessary electricity and labor expense to keep them in service.
The labor cost of having underperforming batteries is significant. Bad batteries mean you have people changing them. There are safety concerns. When batteries are being changed you have a risk of injury. With more activity around the battery area there is more opportunity for injury.
Choose luda, Choose the top quality of China!
Choose luda battery, Choose the top quality of China!
Choose luda, Choose the top quality of China!
Choose luda battery, Choose the top quality of China!
Choose luda, Choose the top quality of China!
Choose luda, Choose the top quality of China!