高氮钢复合焊接接头组织性能分析  

Analysis of microstructure properties of welded joint of high nitrogen steel by hybrid welding

作　　者：李欣欣 张宏[1] 刘凤德[1] 刘双宇[1] 徐春鹰[1] LI Xinxin;ZHANG Hong;LIU Fengde;LIU Shuangyu;XU Chunying(College of Mechanical and Electric Engineering,Changchun University of Science and Technology,Changchun 130022,China)

机构地区：[1]长春理工大学机电工程学院,长春130022

出　　处：《激光技术》2018年第3期341-345,共5页Laser Technology

摘　　要：为了研究在不同热输入下高氮钢焊接接头各区微观组织和硬度分布,采用了Nd∶YAG-MAG电弧复合焊接方法焊接高氮奥氏体不锈钢,进行了理论分析和试验验证,取得了不同热输入下焊接接头各区形貌、微观组织和显微硬度数据。结果表明,高氮钢复合焊接接头截面形貌呈"高脚杯"状,上部为电弧作用区,下部为激光作用区;焊缝组织由奥氏体和少量铁素体组成,随着热输入的增加,铁素体含量增多,铁素体树枝晶主干增长、增粗,有二次支晶分布在树枝晶主干两侧;焊接接头硬度分布不均匀,母材硬度最高,其值在330HV^370HV之间,焊缝区硬度在260HV^300HV之间;随着热输入的增加,焊接接头硬度降低;焊接接头没有出现软化区。这一结果对高氮钢复合焊接在不同热输入参量下获得良好焊缝提供了理论基础。In order to study microstructure and microhardness distributions of welded joint of high nitrogen steel at different heat inputs,high nitrogen austenitic stainless steel was welded by Nd∶YAG-MAG hybrid welding technology.After theoretical analysis and experimental verification,microstructures and microhardness data of the welded joint were obtained under different heat inputs.The results show that,hybrid welding joint of high nitrogen steel cross-sectional is“goblet”shape.The upper is arc action area,and the lower is laser action area.The microstructure consists of austenite and a small amount of ferrite.With the increasing of heat input,the ferrite fraction increases,the ferrite branch crystal trunk grows longer and thicker,and the secondary dendrites is distributed on both sides of the branch crystal trunk.The microhardness distribution of welded joint is not uniform.The hardness of base metal zone is the highest and the value is between 330HV^370HV.The hardness of welding is the lowest,and the value is between 260HV^300HV.The hardness of welded joint decreases with the increasing of heat input.There is no soft zone in welded joint.The study provides a theoretical basis for the welding of high nitrogen steel under the certain heat input parameters.

关 键 词：激光技术 激光-电弧复合焊接 高氮钢 硬度 微观组织 

分 类 号：TG456.7[金属学及工艺—焊接]