What are the characteristics of heat treatment of 60simn steel?
60simn steel is a common alloy spring steel. The quenching medium for heat treatment is 25 ~ 30mm in oil cooling. The elastic limit, yield strength and tempering stability of heat treatment quenching and tempering are good. The defect of heat treatment is strong decarburization tendency. The heating temperature of conventional heat treatment is 860 ~ 870 ℃ and oil cooling. Because of its excellent performance in the use of tools and dies, there are many heat treatment process specifications, including 800 ~ 820 ℃ sub temperature quenching and 950 ℃ high temperature heating quenching treatment.
According to the basic characteristics of heat treatment of 60simn steel, slight decarburization in actual production has obvious influence on the hardness of the workpiece. The hardness of the steel can not reach 58hrc after being heated in oil at 860 ~ 870 ℃. In addition, the hardness of 60simn steel with carbon content less than 0.58% can not meet the requirement of above 58hrc after being heated in oil at 860 ~ 870 ℃.
For 60simn steel with diameter of 25 ~ 30mm, when the hardness standard is 58 ~ 62Hrc, the quenching medium after heat treatment and quenching should be water oil double liquid quenching medium, otherwise it can not meet the technical requirements.