Slide Plate


Slide gate nozzle is equipment installed at ladle or tundish bottom to control steel liquid flow rate, it is composed of upper and lower nozzle bricks, upper and lower slide plate. Slide plate is key component of slide gate nozzle. Compared with traditional sleeve bricks, plugging blocks and nozzle bricks combined control system, slide gate nozzle control system has the following advantages: simpler operation, safer, more reliable, more accurate flow rate control, lower refractory consumption and faster ladle turnaround.

  1. Alumina Carbon Slide Plate

Slide plate is core component of slide gate nozzle, its working condition is very harsh: steel liquid washout, slag corrosion and oxidization, thermal impact, slide abrasion and so on. So slide plate should have high mechanical strength at high temperature, good abrasion resistance, slag corrosion resistance, spalling resistance and so on. Alumina carbon slide plate and alumina zirconia carbon slide plate are most often used slide plates, they feature in excellent thermal shock resistance, spalling resistance and corrosion resistance. Especially for small size electric furnace and tundish, alumina carbon slide plate has  significant service life.

Alumina zirconia  carbon slide plate is made on the basis of alumina carbon slide plate, low thermal expansion rate zircon mullite aggregate is added into raw material to improve thermal shock resistance and corrosion resistance. Besides, fused zirconia corundum or ZrO2 can be used as raw material to further improve slide plate performance.

  1. Slide Plate for High Corrosion Steel Casting

For some kinds of high corrosion steel, such as Ca processed steel, Al-Si killed steel, high oxygen steel and so on, alumina carbon or alumina zirconia carbon slide plate corrosion is severe, service life is significantly decreased. Therefore, low carbon and low silicon alumina carbon slide plate, magnesia slide plate, spinel plate, magnesia carbon slide plate, spinel carbon slide plate, zirconia slide plate and so on are developed to meet special steel casting requirement.

Low carbon and low silicon alumina carbon slide plate is used for high oxygen steel casting. Some quantity of metal aluminum is added into batch material. Low carbon alumina carbon slide plate is heat treated at 500~1000℃, it not only has high hot strength and corrosion resistance of unfired slide plate, but also has high cold strength and high corrosion resistance. At proper heat treatment temperature, Al liquefies and form dense high strength structure, so the corrosion resistance, strength and cracking resistance of slide plate is significantly increased.

Light Burned Alumina Carbon Slide Plate Indexes

Item A B C D
Al2O3 % 70.0 92.0 86.0 75.0
SiO2 % 6.0 2.0 3.5 4.5
ZrO2 % 9.5 / 5.0 5.0
C % 13.0 4.0 4.5 9.0
Apparent porosity % 4.4 6.6 6.5 8.0
Bulk density g/cm3 3.15 3.22 3.25 3.06
Modulus of rupture Mpa 40 27 29 24
Thermal expansion rate(1500℃) % 1.2 0.93 1.08 0.94

 

Basic Slide Plate and Zirconia Inserted Slide Plate

When magnesia or magnesia carbon slide plate is used for Ca treated steel, high oxygen steel and Al-Si killed steel continuous casting, its  corrosion resistance is significantly higher and service life is significantly longer. But it has the shortcoming of lower thermal shock resistance and spalling resistance. By improving craft and introducing Al2O3 into raw material or form sipnel slide plate, thermal shock resistance, spalling resistance and corrosion resistance are significantly increased, they are more suitable for special steel continuous casting than alumina zirconia carbon sliding plate.

Steel Ladle High Corrosion Resistant Basic Slide Plate Indexes

Item GKHB-1 GKHB-2 GKHB-3 GKHB-4
Al2O3 % 82 80 8.1 36
MgO % / / 86 57
SiO2 % 2.3 / / /
ZrO2 % 5.3 8.6 / /
C % 4.5 7.6 3.7 4.5
Apparent porosity % 2.5 4.0 5.8 6.4
Bulk density g/cm3 3.38 3.38 3.11 3.09
Crushing strength Mpa 210 285 215 170
Modulus of rupture Mpa 29 38 23 26
Thermal expansion rate % 0.98 1.09 2.15 1.45