敏化温度对高碳奥氏体不锈钢析出行为及力学性能的影响

采用光学显微镜、扫描电镜、能谱仪、透射电镜等,研究敏化温度对高碳奥氏体不锈钢析出相数量、形态及分布情况的影响,采用拉伸试验机、冲击试验机和布氏硬度仪,分析不同敏化温度下析出相对试验钢力学性能的影响。结果表明,不同敏化温度处理后试样的显微组织均为奥氏体;但随着敏化温度的升高,奥氏体晶界处富Cr碳化物析出增多,以颗粒状和条状形态存在,晶界处析出相尺寸在100~400 nm之间。经650 ℃敏化2 h后试样的强韧性匹配良好,综合力学性能较为优异。

Effect of sensitization temperature on precipitation behavior and mechanical properties of high carbon austenitic stainless steel

Effect of sensitization temperature on quantity, morphology and distribution of precipitates in a high carbon austenitic stainless steel was studied by means of metallographic microscope, scanning electron microscope, energy dispersive spectrometer and transmission electron microscope. The effect of precipitate on mechanical properties of the tested steel at different sensitization temperatures was analyzed by means of tensile testing machine, impact testing machine and Brinell hardness tester. The results show that microstructure of the specimens sensitized at different temperatures is austenite, while with the increase of sensitization temperature, the precipitation of Cr-rich carbides on the austenite grain boundaries increases and exists in granular and strip forms, and the size of precipitates on the grain boundaries is in the range of 100-400 nm. After sensitizing treatment at 650 ℃ for 2 h, the strength and toughness of the specimen match well, and the comprehensive mechanical properties are excellent.