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 Transform Mechanism of Carbides of M42

摘要:

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小时。该工艺下,M42洛氏硬度达到67.2 HRC,抗弯强度达到3115MPa。淬火保温温度通过控制M₆C型碳化物的熔解量,影响最终碳化物的尺寸。 淬火温度为1190℃时,M₆C型碳化物充分熔解,回火过程碳化物均匀弥散析出。

Abstract:

With the raw material of the precision forging M42 spray formed high speed steel, the orthogonal experiment under different parameters was used to optimize the technology of heat treatment and analyze the material’s microstructure, hardness, and flexural strength and the evolution law of carbide in different heat treatment systems. Results show that the best preservation temperature for quenching was 1180℃, and the temperature for temper which should be repeated 3 times and 1h for each time was 540℃. In this system, Rockwell hardness of M42 can reach to 67.2HRC, while flexural strength can be 315MPa.During the process of heat treatment, M₆C carbide was largely affected by the change of quenching preservation temperature. When the quenching temperature was 1190℃, M₆C carbide fully melted, and dispersedly separated after tempering.