X120管线钢激光电弧复合焊热模拟热影响区的组织转变  

Microstructure Transformation of Laser-Arc Hybrid Welding Thermal Simulate Heat Affected Zone of X120 Pipeline Steel

作　　者：付坤 胡连海[3] 王华龙 胡庆福[3] 刘雄 卢立祥 FU Kun;HU Lianhai;WANG Hualong;HU Qingfu;LIU Xiong;LU Lixiang(Hebei Special Equipment Supervision and Inspection Institute,Shijiazhuang 050061,China;Hebei Pressure Equipment Testing and Evaluation Technology Innovation Center,Shijiazhuang 050061,China;Hebei Key Laboratory of Advanced Materials for Transportation Engineering and Environment,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Shang'an Power Plant,HPI,Shijiazhuang 050300,China)

机构地区：[1]河北省特种设备监督检验研究院,河北石家庄050061 [2]河北省承压设备检测评价技术创新中心,河北石家庄050061 [3]石家庄铁道大学河北省交通工程与环境协同发展新材料重点实验室,河北石家庄050043 [4]华能国际电力股份有限公司上安电厂,河北石家庄050300

出　　处：《热加工工艺》2023年第11期63-66,71,共5页Hot Working Technology

基　　金：河北省自然科学基金资助项目(E2022210030);河北省市场监督管理局科研计划项目(2021ZD27)。

摘　　要：X120管线钢具有优异的综合力学性能。采用金相显微镜和透射电镜研究了X120管线钢连续冷却转变(CCT)组织,采用热模拟设备建立了常规热处理条件下的CCT曲线和激光电弧复合焊条件下的模拟热影响区连续冷却转变(SHCCT)曲线。试验结果表明,在激光电弧复合焊条件下,随着冷却速度的增加,热模拟粗晶区组织依次为粒状贝氏体、贝氏体铁素体和板条马氏体,激光电弧复合焊条件下的快速加热使A_(c1)和A_(c3)相变线有所提升,高温停留时间短使得奥氏体来不及长大,使组织细化,激光电弧复合焊条件下的M_(s)转变温度提高,马氏体转变温度区间扩大,使得形成的板条马氏体能够发生自回火,从而减小淬火应力,改善强度和韧性,提高抗开裂能力。X120 pipeline steel has excellent comprehensive mechanical properties.The continuous cooling transformation(CCT)microstructure of X120 pipeline steel was studied using optical microscope and transmission electron microscope.The CCT curve under conventional heat treatment and SHCCT curve of coarse grain heat affected zone under laser-arc hybrid welding were established by thermal simulation equipment.The experimental results show that with the increase of cooling rate,the microstructures of the thermal simulated coarse grain region are granular bainite,bainite ferrite and lath martensite in turn under the condition of laser-arc hybrid welding.The rapid heating during the laser-arc hybrid welding increases the phase change lines of A_(c1) and A_(c3).The short residence time at high temperature inhibits austenite grain growth,therefore,the formed microstructure is refined.The M_(s)transformation temperature under the condition of laser-arc hybrid welding increases and the transformation temperature range of martensite is expanded.Thus,the formed lath martensite undergoes self tempering and the quenching stress reduces,which can improve the strength and toughness,and enhence the crackingresistance.

关 键 词：X120管线钢 激光电弧复合焊 热模拟 CCT曲线 SHCCT曲线 

分 类 号：TG406[金属学及工艺—焊接]