固溶温度对S32750双相不锈钢低周疲劳性能的影响  

Effect of solution temperature on microstructure and low cycle fatigue properties of S32750 duplex stainless steel

作　　者：保顺 丰涵[1] 宋志刚[1] 何建国 顾洋 BAO Shun;FENG Han;SONG Zhigang;HE Jianguo;GU Yang(Research Institute of Special Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司特殊钢研究院,北京100081

出　　处：《钢铁研究学报》2024年第2期217-225,共9页Journal of Iron and Steel Research

摘　　要：通过OM观察、电子背散射衍射技术、显微硬度测试、拉伸及疲劳试验研究了5种固溶温度试验钢的组织形态及低周疲劳性能。结果表明,当固溶温度由1050℃升至1180℃时,试验钢屈服强度与抗拉强度分别提升41、31.5 MPa,低周疲劳寿命延长85%。随着固溶温度的升高,试验钢中α相含量由46.5%升至58.9%,也导致两相内主元素发生再分配,α相内Ni、N含量的增加,使其显微硬度由300提升至324,这是试验钢疲劳寿命提高的原因之一;其二,随着固溶温度的升高,α相内的局部取向差减小,使α相在循环过程中能承受更多载荷,进而提高试验钢低周疲劳寿命。The microstructure and low cycle fatigue properties of five kinds of solid solution temperature test steels were studied by optical microscope,electron backscatter diffraction,microhardness test,tensile and fatigue tests.The results show that the yield strength and tensile strength of the test steel are increased by 41MPa and 31.5MPa,respectively,and the low cycle fatigue life is prolonged by 85%when the solution temperature is increased from 1050℃to 1180℃.The content ofαphase in the tested steel increases from 46.5%to 58.9%and the main elements in two phases are redistributed result from the increase of solution temperature,the increase of ferritic microhardness from 300 to 324 is caused by the increase of Ni and N inαphase,which is one of the reasons for the increase of fatigue lifetime of the test steel;with the increase of solution temperature,the local misorientation in theαphase decrease significantly,and theαphase can withstand more stress during the process of fatigue experiment,it is another important reason for the increase of low cycle fatigue lifetime.

关 键 词：S32750双相不锈钢 相比例 强度 固溶温度 低周疲劳性能 

分 类 号：TG161[金属学及工艺—热处理]