预处理温度对高强度不锈钢力学性能的影响  

Effects of Preliminary Austenitizing Temperature on Mechanical Properties of High Strength Stainless Steel

作　　者：丁雅莉[1] 高齐[1] 王敖 DING Yali;GAO Qi;WANG Ao(Research Institute of Special Steels,Central Iron&Steel Research Institute,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：《新技术新工艺》2024年第12期58-62,共5页New Technology & New Process

摘　　要：借助于力学性能测试、光学金相、X射线衍射、扫描电镜和透射电镜分析技术,对超低温环境使用的高强不锈钢经不同预处理温度处理后力学性能的变化开展了研究。结果表明,当预处理温度为850℃时,试验钢通过逆转变先形成部分奥氏体(非扩散相变),该部分奥氏体使得随后固溶处理的奥氏体内累积更高的缺陷密度。这种高密度缺陷会在马氏体转变过程中保留,提高钢的强度。850℃以下预处理虽然累积的缺陷密度更高,但显著增加最终的残余/逆转变奥氏体量,反而会降低强度。预处理温度不影响低强度版(750℃固溶+250℃回火)的超低温冲击韧性,而850℃预处理的材料屈服和抗拉强度最高,因此推荐为低强度版的预处理温度。虽然高强度版(750℃固溶+500℃回火)屈服和抗拉强度峰值对应的预处理温度同样为850℃,但预处理温度上升,超低温冲击韧性急剧下降,而750℃预处理的材料虽然最终强度略有下降,但超低温冲击韧性甚至高于低强度版(250℃回火),因此推荐为高强度版的预处理温度。By means of mechanical properties test,optical metallography,X-ray diffraction,SEM and TEM analysis technics,it was investigated that the effect of preliminary austenitizing temperature on the mechanical properties of high strength stainless steel for cryogenic application.The results indicated that preliminarily austenitizing at the temperature approximate to 850℃,the sectional austenite was formed with testing steel because of reverse transformation(nondiffusive phase transition),the austenite of this part accumulated higher defect concentration in the subsequent solution treatment austenite,and the high density defects remained during martensite transformation,which improved the steel strength.Preliminary treatment below 850℃accumulated higher defect concentration,but observably increased final residual/reverse austenite contents,which reduced strength.The austenitizing temperature did not affect ultra-low temperature impact toughness of the low-strength version(750℃solution and 250℃annealing)steel,and got highest pretreatment tensile&yield strength after 850℃,therefore low-strength version preliminary austenitizing temperature was recommend.The highstrength version(750℃solution and 500℃annealing)steel also got highest tensile&yield strength at the same 850℃pretreatment,but ultra-low temperature impact toughness decreased sharply while increasing the pretreat temperature.After 750℃pretreatment,tensile strength slightly decreased,but ultra-low temperature impact toughness was higher than that of low-strength version(250℃annealing),therefore the high-strength version pretreatment temperature was recommended.

关 键 词：高强度不锈钢 预处理温度 残余奥氏体 回火处理 强度 超低温冲击韧性 

分 类 号：TH162[机械工程—机械制造及自动化]