采用SLX-80型冷处理系统对淬火Cr5钢进行了不同温度的冷处理, 采用综合物理测试系统的振动样品磁强计选件测试其磁性, 并计算出不同状态Cr5钢中残余奥氏体含量, 测试了不同状态钢的硬度。结果表明: Cr5钢在940 ℃淬火态、－60 ℃和－100 ℃冷处理态的残余奥氏体体积分数分别为14.1%, 12.1%和10.5%, 随冷处理温度的降低, 钢中残余奥氏体含量明显减少; 淬火态钢硬度在940 ℃淬火时最高, 达到65.1 HRC, 淬火后经－100 ℃冷处理后可使钢的硬度提高至66.1 HRC。

SLX-80 cryogenic treatment system was used in cryogenic treatment for Cr5 steel at different temperatures, and magnetization of samples was investigated in vibrating sample magnetometer option of physics property measurement system. The contents of retained austenite in Cr5 steel in different states were calculated. And hardnesses of Cr5 steel in different states were tested. The results show that the volume fractions of retained austenite in the samples quenched at 940 ℃, cryogenic treated at －60 ℃ and －100 ℃ were 14.1%, 12.1% and 10.5%, respectively. When cryogenic treatment temperature increased, the content of retained austenite in the steel reduced obviously. The maximum value of 65.1 HRC in hardness of steel in quenched state could be obtained at 940 ℃, but the cryogenic treatment at －100 ℃ after quenching can make the hardness of steel to further increase to 66.1 HRC.