发动机用SCM435钢的组织与疲劳性能  

Microstructure and fatigue properties of SCM435 steel for engines

作　　者：江畅 陆恒昌 韦习成[1,2] 董瀚[1,2] Jiang Chang;Lu Hengchang;Wei Xicheng;Dong Han(School of Materials and Science Engineering,Shanghai University,Shanghai 200444,China;Zhejiang Institute of Advanced Materials,Shanghai University,Jiashan Zhejiang 314113,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]上海大学(浙江)高端装备基础件材料研究院,浙江嘉善314113

出　　处：《金属热处理》2024年第3期159-163,共5页Heat Treatment of Metals

基　　金：上海市军民融合发展专项资金(2020-jmrh1-kj31)。

摘　　要：采用SEM、TEM以及拉伸测试等研究SCM435钢在870℃淬火、350~650℃回火后的组织和力学性能。结果表明,回火温度为350℃时,其组织是板条马氏体及少量碳化物;随着回火温度的升高,马氏体的板条形态逐渐消失,碳化物沿板条方向析出长大,其中525℃回火后的组织尚有明显的马氏体板条形态并弥散分布着短棒状渗碳体。在试验回火温度范围内调控SCM435钢的力学性能,可以满足8.8~12.9级紧固件的力学性能要求。试验验证了870℃淬火+525℃回火钢的疲劳性能,中值疲劳极限σa50为425 MPa,具有较好的疲劳性能。Microstructure and mechanical properties of SCM435 steel quenched at 870℃and tempered at 350-650℃were studied by means of SEM,TEM and tensile test.The results show that when tempering temperature is 350℃,the structure is martensite lath and a small amount of carbide.With the increase of tempering temperature,the lath morphology of martensite gradually disappears,and carbides precipitate and grow along the direction of lath.The microstructure tempered at 525℃still has obvious martensite lath morphology and short rod cementite is dispersed.By controlling the mechanical properties of the SCM435 steel within the studied tempering temperature range,it can meet the mechanical performance requirements of 8.8-12.9 level fasteners.The fatigue properties of the steel quenched at 870℃and tempered at 525℃is experimentally verified,with a median fatigue limit of 425 MPa,indicating good fatigue properties.

关 键 词：SCM435钢 回火温度 微观组织 力学性能 疲劳性能 

分 类 号：TG156.5[金属学及工艺—热处理]