M42热处理中淬火温度对碳化物转变机制的影响

Effect of Quenching Temperature on Transformation Mechanism of Carbides of M42

以精锻M42喷射成形高速钢为原料,通过热处理正交试验,优化了材料热处理工艺,并分析了不同热处理制度下材料显微组织、硬度、抗弯强度及碳化物的演变规律。结果显示,最佳热处理工艺为:淬火保温温度1180℃,回火温度540℃,回火3次,每次1 h。该工艺下,M42洛氏硬度达到67.2 HRC,抗弯强度达到3115 MPa。淬火保温温度通过控制M_6C型碳化物的溶解量,影响最终碳化物的尺寸。淬火温度为1190℃时,M_6C型碳化物充分溶解,回火过程碳化物均匀弥散析出。

With the precision forged M42 spray formed high speed steel as the raw material, the orthogonal experiment under different parameters was used to optimize the technique of heat treatment and the microstructure, hardness, flexural s trength and the evolution law of carbides were analyzed in different heat treatment systems. Results show that the best preservation temperature for quenching is 1180 °C, and the temperature for temper is 540 °C which should be repeated 3 times and 1 h for each time. In thi s system, Rockwell hardness of M42 can reach to 67.2 HRC, while flexural strength can be up to 3115 MPa. During the process of heat treatment, M_6C carbide is largely affected by the change of quenching preservation temperature. When the quenching temperature is 1190 °C, M_6C carbide fully melts, and precipitates dispersedly after tempering.