发动机用SCM435钢的组织与疲劳性能
Microstructure and fatigue properties of SCM435 steel for engines
江畅 1陆恒昌 2韦习成 2董瀚2
作者信息
- 1. 上海大学材料科学与工程学院,上海 200444
- 2. 上海大学材料科学与工程学院,上海 200444;上海大学(浙江)高端装备基础件材料研究院,浙江嘉善 314113
- 折叠
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.
Abstract
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Key words
SCM435 steel/tempering temperature/microstructure/mechanical properties/fatigue properties引用本文复制引用
基金项目
上海市军民融合发展专项(2020-jmrh1-kj31)
出版年
2024
NETL
NSTL
万方数据