低成本780 MPa级热轧高强钢的组织与性能  

Microstructure and Properties of Low Cost 780 MPa Hot-Rolled High-Strength Steel

作　　者：衣海龙[1] 徐洋[1] 徐兆国[2] 刘振宇[1] 王国栋[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,沈阳110004 [2]天津铁厂,涉县056404

出　　处：《机械工程材料》2010年第12期37-39,共3页Materials For Mechanical Engineering

基　　金：中央高校基本科研业务费资助项目(N090307001);国家自然科学基金资助项目(50271015)

摘　　要：采用热连轧机组和控轧控冷工艺轧制出780MPa级高强钢;并用光学显微镜、透射电子显微镜和拉伸试验机等对其组织与性能进行了研究。结果表明:试验钢的组织主要为细晶铁素体和分布在铁素体晶界处的碳化物;试验钢的屈服强度为730MPa,抗拉强度达到790MPa,应变硬化指数和塑性应变比分别为0.12和0.85,达到了很好的强韧性匹配;细化的铁素体晶粒及尺寸细小的(Nb,Ti)(C,N)析出物有效提高了试验钢的强度。The 780 MPa high-strength steels were prepared by thermo-mechanical control process（TMCP） on hot tandem mill.The microstructure and properties of the steels were investigated by means of optical microscope, transmission electron microscope and tensile test machine.The results show that the microstructure of the tested steel was mainly composed of fine-grained ferrite and carbides distributed along the ferrite grain boundaries.The yield strength and tensile strength of the steel were about 730 and 790 MPa,and the strain hardening exponent and plastic strain ratio were 0.12 and 0.85,respectively,providing well-matched strength with toughness.The finegrained ferrite and tiny（Nb,Ti）（C,N） precipitates played an effective role in strengthening the steel.

关 键 词：高强钢 控轧控冷 碳化物 析出物 

分 类 号：TG142.1[一般工业技术—材料科学与工程]