High chrome alloy strengthened steel cast shot/sand and manufacturing process thereof

Abstract

The invention relates to high-chrome alloy strengthening cast steel shot / grit and a manufacturing process thereof. The invention relates to alloy cast steel shot or cast steel grit used to clear and strengthen the surface of steel, and a manufacturing process thereof, which belongs to metal abrasive. The cast steel shot / grit is characterized in that the weight percentage is as follows: C: 0.75 percent to 1.00 percent, Cr: 0.60 percent to 1.50 percent, V: 0.05 percent to 0.20 percent, Ti: 0.05 percent to 0.20 percent, Si: 0.40 percent to 1.50 percent, Mn: 0.50 percent to 1.20 percent, P: less than or equal to 0.05 percent, S: less than or equal to 0.05 percent, and the rest is Fe. The high-chrome alloy steel shot belongs to the scope of eutectoid steel, and the adding of alloy elements improves the eutectic temperature of 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] High chromium alloy strengthened cast steel shot / sand and its manufacturing process. The invention relates to an alloy cast steel shot or cast steel sand and its manufacturing process 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 ...

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.