Adopting excellent white corundum,flake graphite etc,and produced with scientific process and strict technology,which has perfect anti-thermal shock,anti-corrosion,anti-erosion and anti-oxidation properties.
Monoblock Stoppers
Adopting excellent white corundum,flake graphite etc,and produced with scientific process and strict technology,which has perfect anti-thermal shock,anti-corrosion,anti-erosion and anti-oxidation properties.
Basic Info
| Items | Body | Stopper Rod | ||
| Alumina-Graphite | Magnesia-Graphite | |||
| Chemical Composition(% ) | ALO | ≥45 | ≥75 | --- |
| Mgo | --- | --- | ≥75 | |
| C+SiC | ≥25 | ≥10 | ≥10 | |
| Bulk Density(g/cm³) | ≥2.50 | ≥2.75 | ≥2.70 | |
| Apparent Porosity(%) | ≤20 | ≤16 | ≤16 | |
| Cold Crushing Strength(MPa) | ≥20 | ≥25 | ≥20 | |
| Modulus of Rupture-Room Temp(MPa) | ≥7.0 | ≥7.0 | ≥5.0 | |
| Thermal Shock Resistance (sequence) | ≥5 | ≥5 | ||
Core Highlights
Reliable Monoblock Stoppers for Precise Tundish Steel Flow Control
Monoblock stoppers are critical functional refractory components used in continuous casting to control the flow of molten steel from the tundish into the mold.
Installed inside the tundish and operated together with the tundish nozzle or submerged entry nozzle, the monoblock stopper regulates the opening between the stopper head and nozzle. This allows operators to control molten steel flow and maintain a stable casting process.
Qingdao Dongye Refractory Material Co., Ltd. manufactures monoblock stoppers for continuous casting applications and provides customized refractory solutions according to caster type, steel grade, tundish configuration and operating conditions.
A monoblock stopper, also called a stopper rod, is a refractory flow-control component installed in the tundish.
During casting, the stopper is connected to an external operating mechanism that moves the stopper vertically. The position of the stopper head relative to the tundish nozzle controls the passage available for molten steel.
Its main functions include:
· Regulating molten steel flow from the tundish to the mold
· Maintaining a stable casting flow rate
· Supporting stable mold steel-level control
· Helping control the start and end of casting
· Working together with the tundish nozzle or SEN
· Supporting stable continuous casting operation
For steel plants, stopper performance directly affects the reliability of tundish flow control. A stopper that wears too quickly, cracks or loses sealing accuracy can affect casting stability and increase operational risk.
A monoblock stopper operates in one of the most demanding areas of a continuous casting system.
During service, the refractory is exposed to:
· High-temperature molten steel
· Rapid temperature changes
· Continuous steel-flow erosion
· Tundish slag
· Chemical corrosion
· Mechanical movement
· Repeated opening and closing operations
The stopper head is particularly important because it works together with the tundish nozzle to regulate the steel-flow passage.
If the stopper head or nozzle wears unevenly, the flow characteristics can change during casting.
For this reason, selecting a monoblock stopper should involve more than simply matching its overall dimensions.
The main function of a monoblock stopper is to regulate the flow of molten steel from the tundish to the mold.
Accurate stopper movement and a stable stopper-head/nozzle interface help operators control the steel-flow rate according to casting requirements.
Consistent refractory dimensions are therefore essential.
The stopper is exposed to severe thermal conditions during preheating and casting.
Rapid temperature changes can generate thermal stress within the refractory body.
A suitable refractory structure should provide adequate thermal shock resistance to reduce the risk of cracking during operation.
The stopper head is continuously exposed to flowing molten steel.
Progressive erosion can change the geometry of the stopper head and influence the opening between the stopper and tundish nozzle.
Good erosion resistance helps maintain more consistent flow-control characteristics throughout the casting sequence.
The stopper may operate in contact with tundish slag, particularly around the slag-line area.
Chemical attack can accelerate refractory wear and reduce the usable service life of the stopper.
Material selection should therefore consider the actual slag chemistry and steelmaking conditions.
At the end of a casting sequence, the stopper must work together with the tundish nozzle to restrict or shut off molten steel flow.
A properly designed stopper head and matching nozzle help provide reliable flow control during this operation.
The geometry of the stopper head, rod body and connection area must remain within the required dimensional tolerances during service.
Dimensional accuracy is particularly important where the stopper operates together with a specific tundish nozzle.
The appropriate refractory composition depends on the customer’s steel grade and operating conditions.
Depending on the application, different alumina-, magnesia-, zirconia- or composite-based refractory configurations can be considered for specific stopper sections.
Common considerations include:
· Steel grade
· Casting temperature
· Tundish slag composition
· Casting speed
· Casting sequence
· Steel cleanliness requirements
· Required service life
· Erosion conditions
· Corrosion conditions
The stopper head and body do not necessarily need to have exactly the same performance requirements.
For demanding applications, the refractory configuration can be designed to provide enhanced resistance in areas exposed to molten steel or slag.
The stopper head is the most critical working area of the monoblock stopper.
It directly interacts with the tundish nozzle and molten steel.
Important design considerations include:
· Head geometry
· Head diameter
· Contact/sealing area
· Refractory composition
· Resistance to steel erosion
· Resistance to slag corrosion
· Thermal shock resistance
The correct head configuration should be matched to the customer’s tundish nozzle and casting system.
For applications where nozzle clogging is a recurring problem, an argon-purging configuration may be considered.
Argon can be introduced through a suitable stopper/nozzle arrangement to help reduce the accumulation of non-metallic deposits in the steel-flow passage.
However, argon purging is not a universal solution for every clogging problem.
Nozzle clogging can also be influenced by:
· Steel chemistry
· Deoxidation practice
· Non-metallic inclusions
· Casting temperature
· Refractory interaction
· Argon flow conditions
· Nozzle geometry
Therefore, recurring clogging should be evaluated as a complete steelmaking and continuous casting problem.
Choosing a stopper only by length or diameter can result in an unsuitable product.
We recommend evaluating the following information.
The stopper requirements can vary between:
· Billet casters
· Bloom casters
· Slab casters
· Thin slab casters
· Other continuous casting systems
The stopper must match the tundish nozzle with which it operates.
Provide the nozzle drawing or existing stopper/nozzle dimensions whenever possible.
Steel chemistry can affect refractory corrosion, erosion and nozzle clogging.
Low-carbon, alloy, stainless and other specialty steel grades may require different refractory considerations.
The actual operating temperature affects thermal shock and refractory wear.
Longer casting sequences generally require greater resistance to erosion, corrosion and thermal damage.
The chemical characteristics of tundish slag can significantly influence the wear of the stopper head and slag-line area.
If your current monoblock stoppers experience:
· Head erosion
· Cracking
· Slag-line corrosion
· Premature wear
· Leakage or poor shut-off
· Unstable steel flow
· Nozzle clogging
· Short service life
please provide the failure information.
Understanding where and how the stopper fails can help determine whether the issue is related to material selection, geometry, installation or operating conditions.
Dongye can provide customized stopper solutions for different continuous casting applications.
For billet casting, stopper dimensions and refractory performance should be matched to the tundish nozzle and casting sequence.
Bloom casters can involve larger steel-flow requirements and different tundish configurations. The stopper should therefore be designed according to the specific caster.
Slab casting may require specific stopper dimensions and refractory performance depending on casting speed, steel grade and tundish design.
Thin slab casting has its own flow-control requirements. Stopper and nozzle geometry should be considered together with the thin slab casting system.
Monoblock stoppers are functional refractory components that directly control molten steel flow. Consistent manufacturing quality is therefore essential.
Qingdao Dongye Refractory Material Co., Ltd. has independent R&D and quality-control capabilities, supported by production equipment, manufacturing technology and testing facilities.
Our quality-control process focuses on maintaining consistency from raw material preparation through finished-product inspection.
Depending on the confirmed product specification, quality control can include:
· Raw material inspection
· Material formulation control
· Manufacturing-process control
· Dimensional inspection
· Surface inspection
· Physical-property testing
· Finished-product inspection
For customized products, manufacturing is carried out according to the confirmed technical specification, customer drawing or approved sample.
Different steel plants can use different tundish designs, nozzles and operating mechanisms.
Dongye therefore supports customized monoblock stopper production.
Customers can provide:
· Existing stopper drawing
· Tundish nozzle drawing
· Product sample
· Stopper dimensions
· Caster type
· Steel grade
· Casting temperature
· Casting speed
· Casting sequence
· Current service life
· Existing failure problems
Based on this information, our technical team can evaluate the application and recommend a suitable refractory configuration.
Qingdao Dongye Refractory Material Co., Ltd. is a professional manufacturer of functional refractories for the steel industry.
Our continuous casting refractory products include:
· Monoblock stoppers
· Submerged entry nozzles
· Quick-exchange SENs
· Ladle shrouds
· Tundish upper nozzles
· Long nozzles
· Zirconia sizing nozzles
The company integrates design, R&D, manufacturing, construction and international trade.
Dongye has supplied refractory products to dozens of medium and large steel enterprises in China, with products also exported to Europe, America and Southeast Asia.
The company also provides tundish refractory contracting services, giving our technical team practical experience with the coordinated use of refractory components in continuous casting.
Dongye focuses on refractory products used in steelmaking, continuous casting, precision casting and metal melting.
We consider the interaction between the stopper, tundish nozzle, steel grade, slag and casting conditions when evaluating product requirements.
Monoblock stoppers can be manufactured according to customer drawings, samples and equipment requirements.
Dongye maintains independent R&D and quality-control capabilities and continuously improves materials, manufacturing processes and product consistency.
Because we manufacture monoblock stoppers together with tundish nozzles, SENs, ladle shrouds and other functional refractories, we can evaluate the stopper as part of the complete molten-steel flow-control system.
Dongye products have been supplied to steel enterprises in China and exported to Europe, America and Southeast Asia.
Looking for monoblock stoppers for continuous casting?
Send us your existing stopper or tundish nozzle drawing, dimensions or sample together with your steel grade and casting conditions.
Our technical team can evaluate the application and recommend a suitable stopper material, head design and overall configuration.
Qingdao Dongye Refractory Material Co., Ltd.
Professional manufacturer of functional refractories for steelmaking and continuous casting.
Contact us for a customized monoblock stopper solution and quotation.
FAQ
Q: What is a monoblock stopper?
A: A monoblock stopper is a refractory stopper rod installed inside a tundish to regulate molten steel flow from the tundish into the mold during continuous casting.
Q: What does a monoblock stopper do?
A: The stopper controls the opening between the stopper head and tundish nozzle. By adjusting this opening, the steel flow into the mold can be regulated.
Q: What is a monoblock stopper made of?
A: The refractory composition depends on the application. Different alumina-, magnesia-, zirconia- or composite-based materials can be considered according to steel grade, slag conditions, temperature and required service life.
Q: What is the difference between a monoblock stopper and a conventional stopper?
A: A monoblock stopper is manufactured as an integrated refractory component. The integrated structure can reduce potential weak points associated with multiple refractory connections.
The actual design and manufacturing method should be selected according to the customer’s tundish system.
Q: Can a monoblock stopper be used with an SEN?
A: Yes.
The monoblock stopper works with the tundish nozzle system, which may feed into a submerged entry nozzle. The stopper and nozzle dimensions must be properly matched.
Q: Can you provide argon-purging stoppers?
A: Argon-purging configurations can be considered for applications where argon protection is required.
The exact design should be confirmed according to the customer’s existing tundish and gas-purging system.
Q: How can I reduce nozzle clogging?
A: Clogging can involve steel chemistry, inclusions, deoxidation products, temperature, refractory interaction and argon conditions.
The stopper and nozzle system should be evaluated together rather than treating clogging as a refractory problem alone.
Q: What information is required for a quotation?
A: For a more accurate technical recommendation, please provide:
· Stopper drawing or sample
· Matching tundish nozzle drawing
· Caster type
· Steel grade
· Casting temperature
· Casting speed
· Casting sequence
· Tundish configuration
· Current stopper service life
· Existing failure problems
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