深冷处理后SKD11钢组织与冲击磨料磨损机理研究

Study on microstructure and impact and abrasion mecha⁃nism of SKD11 steel after cryogenic treatment

利用金相显微镜、扫描电子显微镜、硬度计和冲击试验机观察并测试了淬火+深冷处理+回火处理(简称“深冷处理”)后SKD11钢的显微组织、硬度和冲击性能,利用MLD-10型动载荷磨损试验机测试了该工艺下SKD11钢的冲击磨料磨损性能,并对冲击磨料磨损的机理进行了分析。研究结果表明:深冷处理后SKD11钢的组织由隐晶马氏体、残余奥氏体和不同种类的碳化物组成,碳化物包括共晶碳化物、未熔碳化物和点状碳化物。深冷处理SKD11钢的硬度为59.2 HRC,无缺口试样的冲击功约为16 J。在冲击磨料磨损试验中,深冷处理的SKD11钢磨损量随磨损时间近似呈线性增加,在所研究的磨损时间内,深冷处理后SKD11钢前期的磨损机理主要为微观切削磨损和多次塑性变形磨损,后期的磨损机理主要为应变疲劳磨损。

The microstructure and mechanical properties of SKD11 steel after quenching,cryogenic treatment and tempering(abbreviated to cryogenic treatment)were observed and tested by metal⁃lographic microscope,scanning electron microscope,hardness tester and impact tester.The MLD-10 dynamic load wear tester was used to test the impact and abrasive property of SKD11 steel un⁃der the cryogenic treatment process,and the wear mechanism was analyzed.The results showed that the structure of SKD11 steel was composed of tempered martensite,retained austenite and dif⁃ferent carbides in the cryogenic treatment process.The carbides were mainly eutectic carbides and unmelted carbides.Under the cryogenic treatment,the hardness of the SKD11 steel was 59.2 HRC,and the impact energy of the unnotched sample under normal temperature was about 16 J.In the impact and abrasive wear test,the amount of wear of the cryogenic SKD11 steel increased al⁃most linearly with the wear time.During the wear time studied,the wear mechanism of SKD11 steel after cryogenic treatment was mainly micro-cutting wear and plastic deformation wear in the early stage and strain fatigue wear in the later stage.