Manufacturing process of high chrome alloy strengthened steel cast shot/sand

Abstract

The invention relates to a process for manufacturing a high-chrome alloy strengthening cast steel shot / grit and belongs to the metal abrasive materials. The process comprises the following steps: smelting and obtaining a molten steel with a weight percentage of: 0.75 percent to 1.00 percent of C, 0.60 percent to 1.50 percent of Cr, 0.05 percent to 0.20 percent of V, 0.05 percent to 0.20 percent of Ti, 0.40 percent to 1.50 percent of Si, 0.50 percent to 1.20 percent of Mn, P<= 0.05 percent, S<= 0.05 percent, and the balance of Fe, adding FeSiMg8RE7 which accounts for 0.2-0.5% of the molten steel total weight for a modification, at a quenching temperature of 835 DEG C, using water as a quenching agent, and medium temperature tempering. The high-chrome alloy steel shot belongs to the scope of eutectoid steel, and the addition of alloy elements improves an eutectic temperature of the steel and prevents carbon from spreading. Therefore, the quenching temperature can be improved, which is good for pearlite to transform into austenite and the carbon to spread. Fine texture is changed to tempered martensite and tempered troostite. The carbide network of the alloy is lower than or equal to Grade 2 and basically kept to be Grade 1, which is higher than the international GB6484 / 6485-86; the standard carbide network is lower than or equal to Grade 3.

Description

technical field [0001] A preparation method of high chromium alloy reinforced cast steel shot / sand, the invention relates to a preparation method of high chromium alloy reinforced cast steel shot / sand used for cleaning and strengthening the surface of steel, belonging to metal abrasives. Background technique [0002] my country's current steel shot / sand material has been using the national standard GB6484 / 6485-86. Chemical composition of high carbon cast steel shot / sand: C 0.85-1.20%, Si 0.40-1.50%, Mn 0.60-1.20%, P≤0.05% S≤0.05%. , there are two kinds of defects: one is that due to the high carbon content, there is a serious composition segregation phenomenon in the metallographic structure during rapid cooling and forming, and a large amount of secondary cementite is distributed at the grain boundary, and the carbon atoms are supersaturated. The martensite presents an irregular flaky structure, resulting in a large number of microscopic cracks on the surface of the cast s...

AI Technical Summary

Problems solved by technology

Chemical composition of high carbon cast steel shot / sand: C 0.85-1.20%, Si 0.40-1.50%, Mn 0.60-1.20%, P≤0.05% S≤0.05%. , there are two kinds of defects: one is that due to the high carbon content, there is a serious composition segregation phenomenon in the metallographic structure during rapid cooling and forming, and a large amount of secondary cementite is distributed at the grain boundary, and the carbon atoms are supersaturated. The martensite presents an irregular flaky structure, resulting in a large number of microscopic cracks on the surface of the cast steel shot / sand

The second is that after quenching and tempering treatment of steel shot, although the metallographic structure has been improved to a certain extent, the microscopic cracks in the performance are further expanded, resulting in the tensile strength, impact toughness and wear resistance of the steel shot / sand not reaching the ideal state , the service life is generally 1200-1400 cycles

The service life is 30% longer than that of the national standard product, but it still cannot meet the requirements of higher strength. At the same time, when the fatigue limit is reached, the steel shot will burst suddenly and the particle size combination will be uneven.