Slide Gate Plate
A refractory flow-control plate in the ladle sliding-gate mechanism that regulates molten steel from the ladle to the tundish.
FerrumX slide gate plates span high-alumina and alumina-zirconia-carbon grades — operating at 1500–1700°C with sliding-face flatness held to ≤ 0.05 mm, controlling flow across BOF, EAF, LF, VD/VOD and continuous-casting lines.
What it is
What a Slide Gate Plate Is & Where It Is Used
The ladle slide gate plate controls the flow of molten steel from the ladle to the tundish. It is a refractory component installed in the ladle sliding-gate mechanism and is a key part of the steel continuous casting process. The condition of the slide plate affects the stability of the molten steel flow, the smoothness of the continuous casting process, and the quality of the final steel.
During tapping, the slide plate changes the opening size through the sliding mechanism so that molten steel enters the tundish at the set flow rate. This stabilizes casting and supports ingot quality. In the ladle flow-control system the slide plate works together with nozzles and seat bricks to keep the molten steel flow stable and safe. High-quality slide plates resist high temperature, corrosion, and thermal shock, and have low porosity, which extends ladle service life and improves plant productivity.
In continuous casting the slide gate replaced the older stopper-rod system in most modern steel plants because it provides more precise flow control, better safety, and lower maintenance. The slide gate assembly consists of a fixed (upper) plate, a sliding (lower) plate, and a collector nozzle; sliding the lower plate aligns or misaligns the bore holes to start, regulate, or stop the flow.
Slide plates operate in a working temperature range of about 1500–1700°C, depending on steel grade and material type. They are supplied to match common gate systems (including Vesuvius, RHI Magnesita, INTERSTOP, and Krosaki) with bore diameters typically from 50 mm for small ladles to 120 mm for large ladles.
Technical Specifications
Technical Specifications
The tables below list the chemical composition and physical properties of the FerrumX high-alumina and alumina-zirconia-carbon slide plate grades. Values are minimum (≥) or maximum (≤) specification limits. Two conditions are reported: non-impregnated and tar/oil-impregnated plates.
High-alumina slide gate plate
| Property | Condition | HBLT80 | HBLT75 | HBLT70 |
|---|---|---|---|---|
| Al₂O₃ (%) | – | ≥ 80 | ≥ 75 | ≥ 70 |
| C (%) | – | ≥ 2 | ≥ 3 | ≥ 3 |
| Apparent Porosity (%) | Non-impregnated | ≤ 13 | ≤ 13 | ≤ 13 |
| Apparent Porosity (%) | Impregnated | ≤ 10 | ≤ 10 | ≤ 10 |
| Bulk Density (g/cm³) | Non-impregnated | ≥ 2.90 | ≥ 2.85 | ≥ 2.75 |
| Bulk Density (g/cm³) | Impregnated | ≥ 2.95 | ≥ 2.90 | ≥ 2.85 |
| Cold Crushing Strength (MPa) | Non-impregnated | ≥ 80 | ≥ 70 | ≥ 60 |
| Cold Crushing Strength (MPa) | Impregnated | ≥ 100 | ≥ 90 | ≥ 80 |
Alumina-zirconia-carbon slide gate plate
| Property | Condition | HBLTG80 | HBLTG75 | HBLTG70 | HBMLT80 |
|---|---|---|---|---|---|
| Al₂O₃ (%) | – | ≥ 80 | ≥ 75 | ≥ 70 | – |
| Al₂O₃ + MgO (%) | – | – | – | – | ≥ 80 |
| C (%) | – | ≥ 3 | ≥ 3 | ≥ 4 | ≥ 3 |
| ZrO₂ (%) | – | ≥ 4 | ≥ 4 | ≥ 4 | – |
| Apparent Porosity (%) | Non-impregnated | ≤ 13 | ≤ 13 | ≤ 13 | ≤ 13 |
| Apparent Porosity (%) | Impregnated | ≤ 10 | ≤ 10 | ≤ 10 | ≤ 10 |
| Bulk Density (g/cm³) | Non-impregnated | ≥ 3.00 | ≥ 2.95 | ≥ 2.90 | ≥ 2.75 |
| Bulk Density (g/cm³) | Impregnated | ≥ 3.05 | ≥ 3.00 | ≥ 2.95 | ≥ 2.80 |
| Cold Crushing Strength (MPa) | Non-impregnated | ≥ 90 | ≥ 90 | ≥ 80 | ≥ 70 |
| Cold Crushing Strength (MPa) | Impregnated | ≥ 110 | ≥ 110 | ≥ 100 | ≥ 90 |
Material grade comparison
| Type | Main Components | Suitable Environment | Main Performance |
|---|---|---|---|
| High Alumina Slide Plate | Al₂O₃ ≥ 75% | General molten steel flow control | High-temperature resistance, erosion resistance, cost-effective |
| Alumina-Carbon Slide Plate | Al₂O₃ + C | Medium and low carbon steel casting | Thermal shock resistance, erosion resistance, strong adaptability |
| Alumina-Zirconia-Carbon Slide Plate | Al₂O₃ + ZrO₂ + C | Ultra-high temperature, special steel grades | High erosion resistance, oxidation resistance |
| Magnesia-Carbon Slide Plate | MgO + C | High-temperature, alkaline steel | Strong resistance to alkaline erosion, high-temperature stability |
| Zirconia Slide Plate | ZrO₂ ≥ 80% | Ultra-high temperature, special steel grades | Superior heat resistance, erosion resistance, extended lifespan |
Available material grades
FerrumX supplies the following slide plate grades and material families:
- High-alumina grades: HBLT80, HBLT75, HBLT70
- Alumina-zirconia-carbon grades: HBLTG80, HBLTG75, HBLTG70
- Alumina-magnesia-carbon grade: HBMLT80
- Material families offered: High Alumina, Alumina-Carbon (Al₂O₃-C), Alumina-Zirconia-Carbon (Al₂O₃-ZrO₂-C), Magnesia-Carbon (MgO-C), and Zirconia (ZrO₂)
Material & Manufacturing
Material & Manufacturing
Slide plates are produced from high-purity refractory raw materials. High-alumina and alumina-zirconia-carbon grades use tabular alumina, carbonaceous materials (graphite), and zirconia-containing materials as main raw materials, with phenolic resin as binder. Anti-oxidants are added to protect the carbon phase from oxidation during service.
Production follows a controlled sequence: raw material inspection, batching and mixing (commonly in high-intensity mixers), high-pressure forming, and high-temperature firing. Firing temperatures for slide plates typically range from 1500°C to 1800°C, depending on the grade. Plates may be delivered unfired, fired, oil-impregnated, or heat-treated.
Dimensional accuracy is controlled so the sliding face stays flat. Industry practice holds the sliding-surface flatness to ≤ 0.05 mm; this flatness limits steel leakage and supports stable sliding contact between the upper and lower plates. Plates are machined to match the customer’s gate frame and bore diameter.
Applications
Applications Across Steelmaking Routes
Converter (BOF) steelmaking
In the converter steelmaking route, the ladle slide gate plate controls the flow of high-temperature molten steel, supports full mixing of alloy additions, and optimizes refining steps such as deoxidation and desulfurization.
Electric Arc Furnace steelmaking (EAF)
In the electric arc furnace route, the slide gate plate controls molten steel flow during downstream refining so that steel enters the tundish smoothly and the continuous casting process stays stable.
Ladle Furnace (LF) refining
In ladle furnace refining, the slide gate plate works with the nozzle system to control the molten steel flow rate precisely, supporting composition adjustment and steel quality.
VD / VOD vacuum refining
During vacuum degassing (VD) or vacuum oxygen decarburization (VOD), the slide gate plate works with the ladle seat brick and sliding nozzle to keep molten steel flowing smoothly in a low-oxygen environment, lowering gas content and improving steel purity.
Continuous casting
In continuous casting, the slide plate adjusts the molten steel flow rate precisely to avoid billet defects caused by flow that is too fast or too slow, supporting high-quality casting and improving billet yield.
Special steel smelting
For high-end grades such as stainless steel, bearing steel, and high-alloy steel, the slide plate works with high-performance seat bricks and nozzles to keep the molten steel flow stable, avoid secondary oxidation, and improve steel purity and property consistency.
Quality & Support
Quality, Certifications & Engineering Support
FerrumX states that quality control is conducted under ISO-certified processes. The quality management system follows ISO 9001, and occupational health and safety align with ISO 45001 principles. These standards support consistent product quality and a controlled production environment.
Production traceability is maintained by lot: raw material batches, mixing, forming, firing, and final inspection are recorded so that each plate set can be traced to its production history and tested physical and chemical results.
- Raw material inspection before batching
- In-process checks on forming density and dimensions
- Final physical and chemical testing (composition, porosity, bulk density, cold crushing strength)
- Sliding-face flatness control ≤ 0.05 mm
- Engineering support for grade selection, bore diameter, and gate-mechanism matching
FAQ
Slide Gate Plate — Frequently Asked Questions
It controls the flow of molten steel from the ladle to the tundish. By sliding the lower plate, the operator aligns or misaligns the bore holes to start, regulate, or stop the flow, keeping the casting speed stable and safe.
Alumina-carbon (Al₂O₃-C) plates suit general carbon and structural steels. Alumina-zirconia-carbon (Al₂O₃-ZrO₂-C) plates are recommended for special, clean, or calcium-treated steels because zirconia improves erosion and oxidation resistance. Magnesia-carbon (MgO-C) plates are used where basic slag carry-over is severe.
Slide plates work in a molten steel and slag environment of about 1500–1700°C. Material choice depends on the steel grade and the peak temperature at the plate bore.
Service life is expressed in heats per plate set. For alumina-carbon and alumina-zirconia-carbon grades, reported life commonly ranges from 2 to 8 heats per set, varying with steel grade, casting speed, slag conditions, and preheating practice.
Plates should be preheated gradually to about 800–1000°C before the first heat to avoid thermal-shock cracking. Cold starts should be avoided.
Common failure modes are bore erosion and enlargement, thermal-shock cracking, alumina clogging of the bore (notably for Al-killed steels), and sliding-face wear. When bore enlargement exceeds about 15–20% of the original diameter, flow control becomes difficult and the plate set should be replaced.
The sliding-face flatness is held to ≤ 0.05 mm. Maintaining this tolerance prevents molten steel leakage between the upper and lower plates.
Yes. Plates are produced to match the customer’s ladle or tundish drawing, gate mechanism, and bore diameter. Bore diameters typically range from 50 mm to 120 mm according to ladle size and required flow rate.
The slide gate replaced the stopper-rod system in most modern plants. It gives more precise flow control, better safety, lower maintenance, and supports emergency shut-off of the molten steel stream.
FerrumX states that quality control follows ISO-certified processes under ISO 9001 quality management, with occupational health and safety aligned to ISO 45001, plus lot-level traceability of raw materials and production.
Get Started
Ready to Specify Your Slide Gate Plate?
Send your ladle or tundish drawing, gate mechanism type, steel grade, and required bore diameter to FerrumX. The technical team reviews the application and recommends a matching material grade and plate configuration with lead time.
Related: Ladle Shroud · Tundish Nozzle · Stopper Rods · Nozzle Filling Compound · Tundish Well Block · Trough & Runners Refractory
