Abstract: Martensite heat resistant steel 1Cr20Co6Ni2WMoV was melted by a vacuum induction fumace with 22.5 kg ingot and forged to 中16 mm bar.Heat treatment process of samples were quenching at 1060 ℃ for 1h oil cooling + cold treatment at -70℃ or- 192 ℃ for 2 h air cooling + tempering at 640 ℃ for 3 h air cooling. Test results showed that with both heat treatment process the structure of steel   1Cr20Co6Ni2WMoV  consisted of high density dislocation tempering lath martensite,residual austenite,δ- ferite and M₂₃C₆.With cold treatment temperature decreased from -70 ℃ to - 192 ℃ the amount of M₂₃C₆ precipitated at grain boundary and the dislocation density in grain inside increased,the a- mount of residual austenite decreased and the tensile and yield strength of steel respectively increased from 1045 MPa and 715 MPa to 1090 Mpa and 760 MPa.

Key words: Cold Treatment, 1Gr20Co6Ni2WMoV Martensite Heat Resistant Steel, Structure, Mechanical Properties

摘要： 马氏体热强钢1Cr20Co6Ni2WMoV用真空感应炉冶炼，锭重22.5 kg并锻成中16 mm棒材。试样经 1060℃1h油冷淬火， -70℃或-192℃2h空冷的冷处理，640 ℃3 h空冷回火处理。试验结果表明， 1Cr20Co6Ni2WMoV钢在热处理后的组织由高密度位错的回火板条马氏体、残余奥氏体、δ-铁素体和M₂₃C₆组成。 随冷处理温度由-70 ℃降至-192℃,晶界上M₂₃C₆析出数量增多，晶内位错密度升高，残余奥氏体含量降低，钢 的抗拉强度和屈服强度分别由1045 MPa和715 MPa提高至1090 MPa和760 MPa。

关键词: 冷处理, 1Cr20Co6Ni2WMoV马氏体热强钢, 组织, 力学性能