固溶温度对S32750双相不锈钢组织和力学性能的影响

Effect of solution temperature on microstructure and mechanical properties of S32750 duplex stainless steel

采用热力学软件计算了不同固溶温度下S32750双相不锈钢的相组成,并通过室温拉伸试验、扫描电镜和EBSD观察,研究了不同固溶温度对S32750双相不锈钢金相组织和力学性能的影响。试验结果表明:软件计算结果与试验结果吻合较好,S32750双相不锈钢经1060℃固溶处理后,σ相消除;随着固溶温度的升高,S32750双相不锈钢中铁素体含量升高奥氏体含量降低;S32750双相不锈钢适合采用1090℃,保温30 min,水冷的固溶制度,固溶处理后屈服强度、抗拉强度分别达到579 MPa和825 MPa,伸长率为37.5%,奥氏体和铁素体两相比例接近1∶1。

The phase proportion at different solution temperatures in S32750 duplex stainless steel was analyzed with thermodynamics software.Effect of solution temperature on mechanical properties and microstructure of S32750 stainless steel was investigated by means of SEM,EBSD and tensile test at room temperature.The results show that the calculated results are in good agreement with test results.Theσphase in the microstructure of S32750 stainless steel is eliminated after solution-treated at 1060℃.The content of ferrite phase increases and austenite phase decreases in S32750 stainless steel with the increase of solution treatment temperature.The suited process of the S32750 duplex stainless steel is solution at 1090℃for 30 min and then water cooling.After solution treatment,the yield strength,tensile strength and elongation reach 579 MPa,825 MPa and 37.5%,respectively.The proportion of ferrite phase and austenite phase is about 1∶1.