500 MPa超级钢的强化方式与显微组织  

Strengthening Mechanism and Microstructure of 500 MPa Ultra-fine Grain Steels

作　　者：杜林秀[1] 孙建伦[2] 杨海峰[2] 张万山[2] 刘相华[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,辽宁沈阳110004 [2]鞍山钢铁集团公司,辽宁鞍山114001

出　　处：《机械工程材料》2006年第6期30-33,共4页Materials For Mechanical Engineering

基　　金：国家高技术研究发展(973)计划资助项目(2003AAG010)

摘　　要：以两种不同成分的低碳钢为研究对象,通过工业轧制及不同工艺的实验室热轧使材料获得不同的显微组织,对其力学性能及显微组织进行了分析研究。结果表明：在晶粒为3μm左右的铁素体基体上引入5%～10%的贝氏体,对屈服强度影响不大,但可以使抗拉强度提高20MPa；添加0．02%的铌,并通过合适的轧制工艺,可以改善细晶强化和沉淀强化的效果,使屈服强度达到520MPa以上,抗拉强度达到620MPa以上。500MPa超细晶钢的强化方式应以细晶强化为主,配合相变强化和沉淀强化,显微组织应为在超细(3～5μm)的铁素体基体上分布适量的贝氏体。The industrial test and lab rolling tests were carried out for two low carbon steels. The samples with different microstructures were obtained and the strengthening mechanism and microstructures through which the products could obtain good mechanical properties were investigated. Introducing 5%-10% bainite in the matrix of ultra-fine ferrite could make the tensile strength increase about 20 MPa. The yield strength and tensile strength could be increased to more than 520 MPa and 620 MPa, respectively, through addition of 0. 02% Nb and suitable TMCP process refinement strengthening was enhanced and precipitation strengthening was also introduced. The strengthening mechanisms for 500 MPa ultra-fine grain steels should be grain refinement strengthening, transformation strengthening and precipitation strengthening.

关 键 词：低碳钢 晶粒细化 铁素体 贝氏体 

分 类 号：TG142.31[一般工业技术—材料科学与工程] TG113.12[金属学及工艺—金属材料]