固溶处理对高铝310S钢组织和性能的影响

Effect of solution treatment on microstructure and properties of high-alumina 310S steel

对铝含量为2%和4%(质量分数)的热轧态310S耐热钢进行不同条件下的固溶处理,用光学显微镜观察了显微组织,用EPMA-1600电子探针分析了组织中各元素分布,并进行了室温拉伸性能测试。结果表明,高铝310S耐热钢在1150℃固溶处理时,随着时间延长晶粒尺寸明显增大,Cr7C3颗粒和Al4C3颗粒含量均大幅度减少,残余的Cr7C3颗粒逐渐聚集长大,并和Al4C3颗粒一起沿晶界呈链条状析出;经1200℃×2 h固溶处理,Cr7C3颗粒完全消失,而Al4C3相少量残余。高铝310S耐热钢合理的固溶处理工艺为:1200℃保温2 h,然后水淬处理,经此工艺处理的试样抗拉强度和屈服强度均高于传统工艺(1150℃×30 min)。

Solution treatment of hot-rolled 310S based steels with 2 mass% , 4 mass% aluminium was conducted. The microstructure and distribution of elements were investigated by optical microscopy and EPMA-1600 electron probe, and tensile property of the alloy was tested at room temperature. The results show that, the grain size of the alloy significantly increases with increasing solution treatment time at 1150 ℃ , the amount of CrTC3 and AI4C3 phases reduces dramatically, the residual CrTC3 phase gathers and grows up gradually and precipitates as a chain with A14C3phase along the grain boundary eventually. After solution treatment at 1200 ℃ for 2 h, there is only small amount of residual Al4C3, and Cr7C3 phases completely disappear. The optimum solution treatment process of 310S steel is solution treated at 1200 ℃ for 2 h and then water cooling. After optimum solution treatment the tensile strength, yield strength of the alloy are better than that of after treated with traditional process （1150 ℃ x 30 min）.