摘要
采用Ti-Cr-B微合金化成分设计、奥氏体再结晶区直接轧制及淬火加低温回火的热处理工艺,开发出低成本的NM400级别高强度、高韧性的低合金耐磨钢板.利用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)等对其组织、性能、断口形貌及析出物进行了研究.结果表明:试验钢的组织主要为高密度位错板条马氏体及分布在板条上的碳化物;抗拉强度≥1 400 MPa,表面硬度≥HV450,-40℃冲击功在60 J以上;钢板淬透性好,厚度方向硬度分布均匀;除固溶强化和细晶强化外,马氏体板条上的大量位错以及10 nm左右的Ti(C,N)析出颗粒起到强烈的硬化作用;经能谱分析,断口韧窝处存在的第二相粒子主要为MnS和Al2O3颗粒,最大尺寸在2μm左右.
The low-alloy and low cost wear-resistant HSLA NM400 steel plate with high toughness was developed by Ti-Cr-B micro alloying,then direct rolling at austenite recrystallization zone with low-temperature tempering after quenching.Its mechanical properties,microstructure,fracture morphology and precipitates were tested and investigated by means of optical microscope（OM）,scanning electron microscope（SEM） and transmission electron microscope（TEM）.The results showed that the microstructure of specimens is mainly composed of the high-density dislocated lath martensites with carbides distributed on them.The tensile strength≥1A4!400A4!MPa,the surface hardness≥HV450 and impact toughness at-40A4!℃60A4!J.With a good hardenability,the steel has a uniform hardness distribution in thickness direction.In addition to the solid solution hardening and grain refinement,a considerable number of the high-density dislocations and Ti（C,N） nano-precipitates play an effective role in hardening.It was found by SEM and EDS that the brittle second-phase particles in fracture dimples are mainly of MnS and Al2O3,whose biggest size is about 2A4!μm.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2011年第2期241-244,共4页
Journal of Northeastern University(Natural Science)
基金
国家重点基础研究发展计划项目(2010CB630800)
国家科技支撑计划项目(2006BAE03A08)
关键词
低合金耐磨钢
力学性能
马氏体
析出物
硬化
low-alloy wear-resistant steel
mechanical property
martensite
precipitate
hardening
作者简介
曹艺（1982-），女，辽宁大石桥人，东北大学博士研究生；
吴迪（1952-），男，辽宁绥中人，东北大学教授，博士生导师．
