Effect of Preheating Temperature on the Cooling Curves of BW Quenching Media

Using KD-CB177 quenching media cooling tester, the cooling curves of 32 oil and 8%BW quenching media was tested and the effect of preheating temperature on the cooling curves of the quenching medias and the hardness of 45 steel was investigated. Results showed that the characteristic temperature, the temperature on the maximum cooling rate and the maximum cooling rate of the 8%BW quenching media decreased with the increasing of the preheating temperature Using 8% BW under the preheating temperature of 50°Cand 32 oil under the preheating temperature of 40°C to [quench the 45 steel, the properties of 45 steel are considerable. So the 8% BW quenching media maybe can be used to substitute the 32 oil under the certain condition.