等温淬火时间对贝氏体球铁组织和性能的影响  

Effect of Austempering Time on Microstructure and Mechanical Properties of Bainite Ductile Cast Iron

作　　者：李继林[1] 李莉平[2] 高萌[1,3] 王孟君[3] 郑开宏[1] 王海艳[1] 

机构地区：[1]广东省工业技术研究院(广州有色金属研究院)金属加工与成型技术研究所,广东广州510650 [2]嘉兴职业技术学院,浙江嘉兴314031 [3]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《铸造技术》2014年第5期920-923,共4页Foundry Technology

基　　金：国家高技术研究发展计划(863计划)项目(2013AA0312 03);广东省战略性新兴产业核心技术攻关项目(2012A090100018);广东省钢铁耐磨材料产业技术路线图项目(2011B050800005);特派员工作站项目(2011 B090600013);船舶用关键零部件制备技术及产业化项目(2011B010300025);省部产学研结合高性能耐磨材料共性技术创新平台项目(2011A091000035)

摘　　要：将球墨铸铁铸件高温奥氏体化后于300℃等温淬火并保温不同时间,得到贝氏体球墨铸铁,研究了保温时间对贝氏体球铁的组织和力学性能的影响。结果表明,当保温时间较短时,奥氏体不稳定,冷却至室温或者经过机加工后会部分转变为马氏体,硬度值较高,但强度及塑韧性较差。适当延长保温时间,会得到稳定的奥氏体+贝氏体组织,具有较好的综合力学性能。保温时间继续延长时,会导致高碳稳定的奥氏体析出碳化物,使贝氏体球铁的强度和塑韧性下降。The bainite ductile cast iron was prepared by cast and isothermally quenching at 300℃ for different times. The effects of austempering time on microstructure and mechanical properties of the bainite ductile cast iron were studied. The results show that, when isothermally quenching for a short time, the part of austenite can be transformed into martensite after machining or cooling to the room temperature, leading to a higher hardness, but poor strength and toughness. Prolonging the austempering time, the stable austenite and bainite can be achieved, which has better comprehensive mechanical properties. If isothermally quenching for too long, the microstructure of the castings contains carbides which made the material brittle.

关 键 词：等温淬火时间 贝氏体球墨铸铁 显微组织 力学性能 

分 类 号：TG156.3[金属学及工艺—热处理]