热循环对9Ni钢接头粗晶热影响区显微组织和低温韧性的影响  

Effects of Thermal Cycle on Microstructure and Cryogenic Toughness of Coarse-Grained Heat Affected Zone of 9Ni Steel Joint

作　　者：杨秀芝[1,2] 张李超 李轩[3] 华文林 杨春杰[1] 董春法[1] 肖新华[1] YANG Xiuzhi;ZHANG Lichao;LI Xuan;HUA Wenlin;YANG Chunjie;DONG Chunfa;XIAO Xinhua(Mechanical and Electrical Engineering College,Hubei Polytechnic University,Huangshi 435003,China;State Key Laboratory of Materials Processing and Die ~ Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Mechanical Engineering College,Wuhan Textile University,Wuhan 430073,China)

机构地区：[1]湖北理工学院机电学院,黄石435003 [2]华中科技大学材料科学与工程学院,材料成形及模具技术国家重点实验室,武汉430074 [3]武汉纺织大学机械学院,武汉430073

出　　处：《机械工程材料》2018年第8期78-82,共5页Materials For Mechanical Engineering

基　　金：华中科技大学材料成形及模具技术国家重点实验室开放基金资助课题(P2018-014); 湖北理工学院校级教研项目(2017C02)

摘　　要：采用Gleeble-3500型热模拟试验机在t8/5(800℃到500℃冷却时间)分别为6,10,30,60,100s下制备了9Ni钢接头粗晶热影响区(CGHAZ)试样,并对试样进行了低温冲击试验,研究了t8/5对CGHAZ显微组织和低温韧性的影响。结果表明:CGHAZ的显微组织主要由板条马氏体组成,当t8/5为30s时,显微组织中出现粒状贝氏体,且其数量随t8/5的延长而增多;随着t8/5的延长,CGHAZ中马氏体板条束尺寸先略有增大后减小,韧脆转变温度先升高后降低;不同t8/5下CGHAZ在-100,-125℃的冲击功都高于200J,随着冲击温度的下降,冲击断口均由韧窝形貌向准解理形貌转变。Coarse-grained heat affected zone（CGHAZ）samples of 9 Ni steel joint were prepared with Gleeble-3500 type thermal simulator at t8/5（cooling time from 800 ℃ to 500 ℃）of 6,10,30,60,100 s,respectively,and then cryogenic impact tests were carried out on the samples.The effects of t8/5 on the microstructure and cryogenic toughness of CGHAZ were investigated.The results show that the microstructure of CGHAZ was mainly composed of lath martensite.The granular bainite appeared at t8/5 of 30 sand the amount increased with increasing t8/5.With increasing t8/5,the size of martensite lath in CGHAZ increased slightly and then decreased;the ductile-brittle transition temperature rose and then decreased.The impact energy at-100℃and-125℃ of CGHAZ prepared at different values of t8/5 was higher than 200 J.With decreasing impact temperature,the impact fracture morphology changed from dimple to quasi-cleavage.

关 键 词：9NI钢 低温韧性 焊接 热循环 粗晶热影响区 

分 类 号：TG142.33[一般工业技术—材料科学与工程]