Study on the Cooling Capacity of Different Quenchant

Heat treatment is one method to improve mechanical properties of metal, but each heat treatment method has its advantages and disadvantages, therefore, different requirements regarding size, shape, and properties with respect to different heat treatment processes should be considered. The traditional liquid quenchant are clear water and quench oil. Gas quenching is a relatively new process with several important advantages, such as minimal environmental impact, clean products, and ability to control the cooling locally and temporally for best product properties. To meet the high cooling rates required for quenching, the cooling gas must flow at very high velocities, but still the cooling capacity of gas is weakness. In order to increase the cooling capacity of gas, the spray water is added during gas quenching. In this paper, the GCr15 steel is as the research object, the cooling capacity of clear water, quench oil, nitrogen and nitrogen-spray water are studied through comparison of temperature difference and cooling velocity of the specimen.