X80钢不同强度匹配打底焊接头的冷裂敏感性  

Cold Cracking Sensitivity of Different Strength Matching Backing Welding Joint of X80 Stee

作　　者：夏培培 杨柳青 靳海成 吴林恩 肖健 袁中明 XIA Peipei;YANG Liuqing;JIN Haicheng;WU Linen;XIAO Jian;YUAN Zhongming(National Engineering Research Center for Oil and Gas Pipeline Transportation Safety,Langfang 065000,China;China Petroleum Pipeline Engineering Co.,Ltd.,Langfang 065000,China;College of Materials Engineering,North China Institute of Aerospace Engineering,Langfang 065000,China;No.4 Branch of China Petroleum Pipeline Research Institute Co.,Ltd.,Langfang 065000,China)

机构地区：[1]油气管道输送安全国家工程研究中心,廊坊065000 [2]中国石油天然气管道科学研究院有限公司,廊坊065000 [3]北华航天工业学院材料工程学院,廊坊065000 [4]中国石油管道局工程有限公司第四分公司,廊坊065000

出　　处：《机械工程材料》2023年第6期61-66,共6页Materials For Mechanical Engineering

基　　金：中国石油集团工程股份有限公司科学研究与技术开发项目(2020ZYGC-01-01);沧州市重点研发“揭榜挂帅”项目(212101005D)。

摘　　要：选用低强、等强和高强匹配的3种低氢型焊条,在80℃预热条件下分别对X80钢板进行U形坡口和斜Y形坡口打底焊,计算了接头断面裂纹率,并进行了维氏硬度测试,评价了等强和高强匹配焊条打底焊接头的冷裂敏感性。结果表明:焊条的冷裂纹敏感指数随强度等级提高而增大,但焊缝表面及断面均未发现裂纹,断面裂纹率为0,说明冷裂敏感性并未随焊条强度增大而增强。与低强匹配焊条打底焊相比,等强和高强匹配焊条打底焊后热影响区硬度未明显增大,即淬硬倾向未明显增大、冷裂敏感性未增强。等强和高强匹配焊条可用于X80钢的打底焊。By using low-strength,equal-strength and high-strength matching low-hydrogen covered electrodes,backing welding was conducted on X80 steel plate under 80℃preheating and with U groove and oblique Y groove.The section crack rate of the joint was calculated,and the Vickers hardness was measured.The cold cracking sensitivity of the backing welding joint with equal-strength and high-strength matching electrodes was evaluated.The results show that the cold crack sensitivity coefficient of the covered electrode increased with increasing its strength grade,but no cracks were found on the surface and section of the weld,whose section crack rate was 0,indicating that the cold cracking sensitivity did not increase with increasing covered electrode strength.Comparing with that by low-strength matching covered electrode backing welding,the hardness of the heat-affected zone by equal-strength and high-strength matching covered electrode backing welding did not increase significantly,namely the hardening tendency did not increase significantly,and the cold cracking sensitivity was not intensified.Equal-strength and high-strength matching covered electrodes could be used for backing welding of X80 steel.

关 键 词：X80钢 焊接材料 强度匹配 打底焊 冷裂敏感性 

分 类 号：TG406[金属学及工艺—焊接]