热输入对Q345R钢埋弧焊接头组织性能的影响  

Influence of Heat Input on Microstructure and Properties of Q345R Steel Submerged Arc Welding Joints

作　　者：胡效东[1] 孙启童 张勇 赫庆坤[3] HU Xiaodong;SUN Qitong;ZHANG Yong;HE Qingkun(College of Mechanical and Electronic Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Shandong Better Machine Co.,Ltd.,Linyi 276600,China;School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学机械电子工程学院,山东青岛266590 [2]山东百特机械设备有限公司,山东临沂276600 [3]山东科技大学材料科学与工程学院,山东青岛266590

出　　处：《热加工工艺》2022年第15期31-35,40,共6页Hot Working Technology

摘　　要：利用埋弧自动焊对16 mm厚的Q345R钢板进行X形坡口对接焊试验,研究热输入对焊接接头组织与力学性能的影响。测量焊接接头横截面的硬度,得到不同焊接热输入下的硬度分布。利用硬度与强度之间的经验公式计算得到接头的屈服强度和抗拉强度分布。结果表明:随焊接热输入的增大,熔深、余高增大,焊缝过热区中块状先共析铁素体体积占比逐渐增大;焊缝、热影响区的硬度均高于母材的,且接头的硬度最大值随热输入的增大而减小。第一道焊缝及热影响区的硬度与强度分布相对均匀,第二道焊缝与热影响区的硬度、强度梯度较大。在最高热输入为41.0 kJ/cm时,焊接接头的屈服强度与抗拉强度均高于母材的。X groove butt welding tests of 16 mm thick Q345R steel plate were carried out by using submerged arc welding,and the effect of heat input on the microstructure and mechanical properties of the welded joint was studied.The hardness of cross section of the welded joint was measured and the hardness distribution under different welding heat input was obtained.The yield strength and tensile strength distribution of the joint were calculated by using the empirical formula between hardness and strength.The results show that with the increase of welding heat input,the penetration and reinforcement increase,the volume fraction of primary eutectoid ferrite in superheated zone of the weld increases gradually.The hardness of the weld and heat affected zone is higher than that of base metal,and the maximum hardness of the joint decreases with the increase of the heat input.The distribution of hardness and strength of weld and HAZ of the first pass is relatively uniform,and the gradient of hardness and strength between weld and HAZ of the second pass is large.When the heat input is the maximum of 41.0 kJ/cm,the yield strength and tensile strength of the welded joint are higher than those of base metal.

关 键 词：Q345R钢 埋弧自动焊 硬度 屈服强度 抗拉强度 

分 类 号：TG407[金属学及工艺—焊接] TG445