复相钢拉伸断口分层原因分析  

Analysis on Cause of Delamination of Tensile Fracture of Duplex-phase Steel

作　　者：葛南飞 金一 张梅[1,2,3] 方平 宫秀勉 GE Nanfei;JIN Yi;ZHANG Mei;FANG Ping;GONG Xiumian(School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China;State Key Laboratory of Advanced Special Steel, Shanghai 200444, China;Shanghai Key Laboratory of Advanced Ferrometallurgy, Shanghai 200444, China;Technology Center of Shanghai Huizhong Automobile Manufacturing Co., Ltd., Shanghai 200122, China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [3]上海市钢铁冶金新技术开发应用重点实验室,上海200444 [4]上海汇众汽车制造有限公司技术中心,上海200122

出　　处：《上海金属》2021年第2期42-48,共7页Shanghai Metals

摘　　要：两种商用800 MPa级复相钢拉伸后分别出现了正常断裂和断口分层两种状态。通过金相显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)、透射电子显微镜(TEM)、维氏硬度计等手段分别对正常断裂和断口分层的试样进行了系统的研究,分析了断口产生分层的机制和主要原因。结果表明:断口分层与试样厚度中心组织偏析带及偏析处局部富集的析出相和大块状TiN颗粒有关,起始于偏析带中的细小析出相与基体界面处;Ti/Mn的析出相及大块状TiN等第二相颗粒导致了试样断口分层。Two kinds of commercial 800 MPa grade duplex-phase steels showed normal fracture and laminated fracture after tensile test,respectively.By means of optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),transmission electron microscope(TEM)and Vickers hardness tester,the samples with normal fracture and laminated fracture were studied systematically,and the mechanism and main cause of fracture delamination were analyzed.The results showed that the fracture delamination was related to segregated band at mid-thickness of the sample and precipitated phase and block-shaped coarse TiN particles concentrated locally in the segregated band,and emanated from the grain boundaries between fine precipitates in the segregated zone and ferrite matrix.The second phase particles such as Ti/Mn precipitated phase and block-shaped coarse TiN resulted in the fracture delamination of the tensile sample.

关 键 词：复相钢 分层断口 偏析带 析出相 

分 类 号：TG1[金属学及工艺—金属学]