回火温度对超高强韧船体结构钢力学性能的影响  

Effect of tempering temperature on the mechanical properties of ultra-high strength and toughness hull structural steel

作　　者：王亚超[1] 吴开明[2] Wang Yachao;Wu Kaiming(International Research Institute for Steel Technology,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Collaborative Innovation Center for Advanced Steels,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学国际钢铁研究院,湖北武汉430081 [2]武汉科技大学高性能钢铁材料及其应用湖北省协同创新中心,湖北武汉430081

出　　处：《武汉科技大学学报》2019年第5期328-333,共6页Journal of Wuhan University of Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2014CB643300);湖北省技术创新专项重大资助项目(2016AAA022)

摘　　要：借助OM、SEM、EBSD及力学性能测试等手段,研究了回火温度对低碳超高强韧船体结构钢显微组织及力学性能的影响。结果表明,经不同温度(500~650℃)回火2 h后,试验钢的显微组织均为回火索氏体,随着回火温度的升高,钢中析出渗碳体数量及大角度晶界含量逐渐增加;力学性能测试结果显示,试验钢的抗拉强度和屈服强度随回火温度的升高而降低,屈服强度在回火温度区间内均在782 MPa以上,达到超高强度船体钢的要求;试验钢的塑性和韧性随着回火温度的升高有所提升,延伸率和室温冲击吸收功分别保持在12%和212 J以上,且当回火温度为650℃时,试验钢于-80℃下的冲击吸收功高达64 J,这主要与钢中大角度晶界含量有关。By means of OM,SEM,EBSD and mechanical performance tests,the effects of tempering temperature on the microstructure and mechnical properties of a low-carbon ultra-high strength and toughness hull structural steel were investigated.The results show that the microstructure of the investigated steel after tempering at different temperatures(500~650℃)for 2 h is tempered sorbite;with the increase of tempering temperature,the amount of precipitated cementite and the content of high-angle grain boundary increase gradually.The results of mechanical tests indicate that the yield strength and tensile strength of the investigated steel decrease with the increase of tempering temperature,and the overall yield strength is above 782 MPa in the tempering temperature range,which meets the strength requirements for ultra-high strength hull steel design.Besides,the plasticity and toughness of the investigated steel increase with the increase of tempering temperature,and the minimum elongation rate as well as room-temperature impact absorbed energy are above 12%and 212 J,respectively,while the impact absorbed energy at-80℃of the steel tempered at 650℃is as high as 64 J.The low-temperature toughness of steel is mainly related to the content of high angle grain boundary.

关 键 词：船体结构钢 高强高韧 回火温度 显微组织 大角度晶界 力学性能 低温韧性 

分 类 号：TG142[一般工业技术—材料科学与工程]