Advantages and disadvantages of several materials commonly used in ladle slide gate
1. High-aluminum slide gate plate
(1) poor erosion resistance, sliding surface and casting mouth erosion is serious.
(2) Poor thermal shock stability, easy to produce cracks in use.
2. Aluminum carbon slide gate plate
Aluminum carbon sliding plate and experienced a non-burning aluminum carbon and sintered aluminum carbon. Unburned aluminum carbon slide gate plate in order to improve the erosion resistance and thermal shock stability, in the granular material added synthetic mullite, rhodochrosite and silicon carbide materials, in the matrix added corundum and silicon carbide.
However, slide gate plate made of this material gradually develops low strength in thermal state, serious wear and tear of the sliding surface and poor cracking resistance during the process of use. The disadvantages of burnt aluminum-carbon bricks are low thermal shock resistance, not being able to be used continuously for many times, and the carbon is easily oxidized in the process of use, with low erosion resistance.
3.Aluminum-Zirconium-Carbon Slide gate plate
Aluminum-zirconium-carbon slide gate plate is developed on the basis of sintered aluminum-carbon slide plate.
This material slide gate plate adopts the low expansion rate of Al2O3-SiO2-ZrO2 system raw materials, made of oblique zircon, mullite, corundum, etc. as the main crystalline phase, characterized by carbon combination of refractory materials, aluminum-carbon slide gate plate has a fairly good performance and applicability, but in many uses of cracking and sliding surface wear is the key to limit the improvement of its life.
Carbon combined with aluminum-carbon and aluminum-zirconium-carbon slide gate plate is the current domestic and foreign steel mills commonly used slide plate material, but these two types of ladle slide plate in the casting of calcium-treated steel, calcium erosion resistance is poor, is not adapted to calcium-treated steel, Al / Si sedentary steel and other steel casting.
4. Magnesia-carbonate and spinel-carbonate slide gate plates
Magnesium slide gate plate was first used in Europe, because magnesium oxide has good anti-mechanical stress performance and chemical erosion resistance, to a certain extent to meet the requirements of casting calcium-treated steel and high oxygen steel. However, the thermal expansion coefficient of magnesium oxide slide gate plate is large, easy to thermal spalling when casting steel, and there is still room for improvement in thermal shock resistance.
Spinel carbon slide gate plate is the use of magnesium-aluminum spinel as the main crystalline phase, characterized by ceramic and carbon composite combination of refractory materials. The coefficient of thermal expansion and modulus of elasticity of magnesium-aluminum spinel materials are smaller than magnesium oxide, and the thermal shock resistance is stronger than magnesium oxide. However, spinel material and steel calcium slow chemical reaction, the generation of low fusion material affects its service life.
5. Zirconia slide plate
The zirconia slide gate plate with hot pressing molding has the characteristics of high temperature strength, low apparent porosity, small pore size of the pores, etc. It has good resistance to steel erosion when used on the intermediate ladle. Zirconia material has good high-temperature performance, but for its cost and other reasons, the industry generally used in the aluminum-carbon slide around the cast hole inlaid zirconia zirconia ring made of composite slide.