At Xintai Refractory, we manufacture premium tundish upper nozzles featuring high-purity zirconia inserts combined with optimized alumina-carbon outer materials. Designed for severe thermal and chemical conditions, our nozzles offer exceptional refractoriness, strong anti-clogging performance, superior resistance to thermal shock, and outstanding erosion/corrosion resistance. These properties enable longer casting sequences, reduced downtime, and enhanced productivity in continuous casting operations.
Our tundish upper nozzles have demonstrated stable performance in large-scale steel plants such as Shagang Group, Azovstal, and Bhilai Steel Plant, earning consistent positive feedback from end users. By adjusting material ratios according to steel grade, slag conditions, protection methods, and casting technology level, we ensure each product fully meets the specific operational requirements of our customers.
Technical Specifications
| Tundish Upper Nozzle Technical Parameters | |
|---|---|
| Brand | Xintai Refractory |
| Product Name | Tundish Upper Nozzle |
| Material Structure | Zirconia Core + Alumina-Carbon Outer Layer |
| ZrO₂ + HfO₂ (Core) | ≥95% |
| Al₂O₃ (Outer) | ≥85% (75–94% customizable) |
| C Content | ≥3% |
| Bulk Density | Core ≥5.2 g/cm³; Outer ≥2.6 g/cm³ |
| Apparent Porosity | Core ≤10%; Outer ≤20% |
| Crushing Strength | Core ≥100 MPa; Outer ≥45 MPa |
| Thermal Shock Resistance | ≥5 Cycles |
| Refractoriness | Up to 1900°C (depending on zirconia grade) |
| Application | Installed at Tundish Bottom to Control Molten Steel Flow in Continuous Casting |
| Packing | Export Wooden Case |
| Storage | Keep Dry, Store Upright, Handle with Care |
Key Features
- Excellent Flow Control Accuracy: Working together with stopper rods, the tundish upper nozzle enables precise molten steel flow adjustment, ensuring consistent casting speed and stable mold level.
- Superior Anti-Clogging Performance: The high-purity zirconia core significantly reduces alumina adhesion and inclusion buildup, minimizing clogging risk during long casting sequences.
- Outstanding Thermal Shock Resistance: With optimized microstructure and controlled expansion rate, our nozzles withstand rapid temperature fluctuations without cracking or spalling.
- Exceptional Erosion and Corrosion Resistance: Resistant to molten steel and aggressive slag attack, the zirconia insert maintains dimensional stability and reduces inner diameter expansion.
- Long Service Life: In 150-ton ladle trials using 95% zirconia inserts, our tundish upper nozzles maintained stable performance for 10–12 hours or longer, supporting extended casting campaigns.
Typical Applications
The tundish upper nozzle is widely used in:
Continuous casting of carbon steel
Alloy steel production
High-manganese steel casting
Free-cutting steel casting
Billet, bloom, and slab casting operations
Production Details of Submerged Entry Nozzle
At Xintai Refractory, tundish upper nozzles are produced under strict quality control:
Raw Material Selection
High-purity zirconia (≥95% ZrO₂) and premium alumina-carbon materials ensure chemical stability and structural strength.Automatic Forming Equipment
Precision pressing and molding equipment guarantee dimensional accuracy and uniform density.High-Temperature Firing
Adequate sintering time ensures excellent bonding strength and thermal stability.Strict Quality Inspection
Each batch undergoes chemical analysis, bulk density testing, porosity measurement, and strength testing before shipment.Customized Material Ratio Adjustment
According to user requirements—steel grade, slag type, protection practice, casting technology level—we adjust the material formulation to maximize performance.
Packing and Shipping Details
Packing: Standard export wooden cases with internal cushioning to prevent impact damage.
Moisture Protection: Products are packed with moisture-proof materials to ensure dryness.
Handling Instructions: Keep upright during storage and transportation. Handle with care to avoid mechanical shock.
Shipping Methods: Sea freight, railway, or truck transportation depending on customer location.
Frequently Asked Questions (FAQ)
Q1: What is the main function of a tundish upper nozzle?
It controls molten steel flow from the tundish to the lower nozzle, working together with the stopper rod to ensure stable casting speed and consistent product quality.
Q2: Why is zirconia used in tundish upper nozzles?
Zirconia offers extremely high refractoriness, low thermal expansion, superior corrosion resistance, and excellent resistance to steel erosion, making it ideal for severe casting environments.
Q3. How long can your tundish upper nozzle operate continuously?
Under normal operating conditions with 95% zirconia insert, service time can reach 10–12 hours or longer depending on steel grade and casting parameters.
Q4: Can you customize the size and material composition?
Yes. We provide customized dimensions, inner diameters, and material formulations based on steel grade, tundish configuration, and casting requirements.
Q5: What measures prevent clogging?
High-density zirconia core, optimized smooth inner surface, and tailored composition reduce inclusion adhesion and alumina buildup, minimizing clogging risk.
