热输入对埋弧焊桥梁钢焊缝金属显微组织和性能的影响  

Effect of Heat Input on Microstructure and Properties of Weld Metal in Submerged-Arc Welded Bridge Steel

作　　者：陈洋 肖丙政 胡兵 李伟 CHEN Yang;XIAO Bingzheng;HU Bing;LI Wei(Nanjing Iron and Steel Co.,Ltd.,Nanjing Jiangsu 210000,China;School of Materials Science and Engineering,Yanshan University,Qinhuangdao Hebei 066000,China)

机构地区：[1]南京钢铁股份有限公司,江苏南京210000 [2]燕山大学材料科学与工程学院,河北秦皇岛066000

出　　处：《上海金属》2025年第1期42-47,55,共7页Shanghai Metals

摘　　要：采用Q345qE~Q420qE桥梁钢配套用大热输入埋弧焊ER55HW焊丝对Q370qEHW钢进行了大热输入(50~150 kJ/cm)埋弧焊接。采用金相显微镜、扫描电子显微镜、透射电子显微镜和能谱分析、冲击试验分析了焊缝金属的组织和性能。结果表明:随着热输入从50 kJ/cm升至150 kJ/cm,焊缝金属中针状铁素体的比例从85%降至59%,大尺寸M-A组元的比例从28.8%升至38.9%,M-A组元在焊缝中的占比也从0.363%增加至0.975%,焊缝金属中夹杂物数量减少,占比从0.41%降至0.25%;随着热输入的增大,焊缝金属冲击断口纤维率递减,-40℃冲击吸收能量从50 kJ/cm时的117 J降至150 kJ/cm时的59 J,纤维区韧窝尺寸增大,从圆形转变为椭圆形,尺寸分布不均匀,放射区解离尺寸增大。Q340qEHW steel was subjected to high heat input(50 to 150 kJ/cm)submerged-arc welding by using ER55HW welding wire which matched Q345qE to Q420qE bridge steels.The microstructure and properties of the weld metal were analyzed via metallographic microscope,scanning electron microscope,transmission electron microscope,energy spectrum analysis,and impact test.The results showed that(a)as the heat input increased from 50 to 150 kJ/cm,the proportion of acicular ferrite in the weld metal decreased from 85%to 59%,the proportion of large-sized M-A components increased from 28.8%to 38.9%,and the proportion of M-A components in the weld also increased from 0.363%to 0.975%,the number of inclusions in the weld metal decreased,and their proportion decreased from 0.41%to 0.25%;and(b)with the increase in heat input,the fiber ratio of the impact fracture of the weld metal showed a degressive trend,and the impact absorbed energy at-40℃decreased from 117 J at 50 kJ/cm to 59 J at 150 kJ/cm;the dimples in the fiber zone exhibited an increase in size and a change from circular to elliptical form,uneven size distribution and an increase in the size of dissociation in the radiation zone.

关 键 词：埋弧焊丝 大热输入 焊缝金属 冲击断口 

分 类 号：TG446[金属学及工艺—焊接]