摘要
针对国内某钢厂生产的低合金超高强度贝氏体钢设计了3种不同锻后冷却+等温退火软化工艺,利用扫描电镜观察不同退火工艺下试验钢的显微组织,并采用布氏硬度计测试其硬度。结果表明:锻后空冷+亚温球化退火工艺下材料显微组织为回火托氏体,碳化物呈断续状或短片状,硬度(HB)为270;而锻后空冷+等温球化退火工艺下显微组织仍为回火托氏体,碳化物则呈粗大条状,硬度(HB)为290;试验钢经锻后炉冷+亚温球化退火工艺处理后,其显微组织转变为回火索氏体,钢中的M-A岛分解,碳化物球化并聚集长大,铁素体发生回复,材料硬度(HB)大幅降低至245,满足切屑加工性能要求。
Three different annealing processes regarding forge cooling and isothermal softening were designed for ultra-high strength low alloy bainite steel produced by a domestic steel plant.The microstructure of the samples under different annealing processes was observed by scanning electron microscope,and the hardness was measured by a Brinell hardness tester.The results show that the microstructure of the materials under air cooling+sub-thermal spheroidization annealing is composed of tempered tortolite,where the carbides are intermittent or patchy,and hardness is 270 HB.The microstructure under air cooling+isothermal spheroidization annealing is still composed of tempered tortolite,where the carbides are thick strips,and hardness is 290 HB.The microstructure under furnace cooling+sub-thermal spheroidization annealing is composed of tempered sostenite,where the M-A islands are decomposed,the carbides are spheroidized and aggregated,and the ferrite is recovered.Hardness of steel with the later process is significantly reduced to 245 HB,which is appropriate for cutting performance.
作者
杜思敏
Du Simin(Special Steel Technology Research Department of Pangang Group Research Institute Co.,Ltd.,Panzhihua 617000,Sichuan,China;State Key Laboratory of Marine Equipment Made of Metal Material and Application,Anshan 114009,Liaoning,China)
出处
《钢铁钒钛》
CAS
北大核心
2020年第5期130-135,共6页
Iron Steel Vanadium Titanium
作者简介
杜思敏(1986—),女,工程师,主要从事工模具钢开发技术研究,E-mail:2926747855@qq.com。
