冷处理及回火次数对刀剪用M390粉末钢组织和性能的影响

Effect of cryogenic treatment and tempering times on microstructure and properties of M390 powder steel for chopping knives and scissors

通过对M390粉末不锈钢进行淬火、冷处理和低温回火,研究了热处理对合金显微组织和力学性能的影响。结果表明:冷处理降低合金中残余奥氏体的数量,大幅度提高材料硬度和抗弯强度;1180℃淬火试样冷处理后,随回火次数的增加,单位面积碳化物颗粒总数和平均粒径增加,硬度下降,一次回火后硬度达到61.1 HRC;1130℃淬火试样冷处理后,随着回火次数增加,单位面积颗粒总数不断增加,平均粒径和硬度下降,一次回火后硬度达到60.0 HRC;淬火温度和回火次数对抗弯强度影响不大,合金抗弯强度为4000 MPa左右。

The effect of heat treatment on microstructure and mechanical properties of M390 powder stainless steel was studied by quenching,cryogenic treatment and low temperature tempering.The results show that cryogenic treatment reduces the amount of residual austenite in the alloy,and greatly increases the hardness and flexural strength of the alloy.After quenched at 1180℃,with the increase of tempering times,the total number of carbides per unit area and average particle size increase,and the hardness decreases.The hardness reaches 61.1 HRC after the first tempering.After quenched at 1130℃,with the increase of tempering times,the total number of particles increases,the average particle size and hardness decrease,and the hardness reaches 60.0 HRC after the first tempering.Quenching temperature and times of tempering have little effect on the bending strength,which is at the level of 4000 MPa.