高功率CO_2激光焊接管线钢接头的组织与性能  

Microstructure and Properties of High Power CO_2 Laser Welded Pipeline Steel

作　　者：胡连海[1] 黄坚[1] 李铸国[1] 吴毅雄[1] 

机构地区：[1]上海交通大学上海市激光制造与材料改性重点实验室,上海200240

出　　处：《中国激光》2009年第12期3174-3178,共5页Chinese Journal of Lasers

基　　金：科技部国际合作重点项目(2006DFB52680);上海市科委国际合作项目(061107030)资助课题

摘　　要：焊接是管线建设的关键技术之一,随着我国管线钢的快速发展,越来越需要匹配的焊接技术来满足管线的建设。分析了激光焊在管道焊接中的优缺点,并采用高功率激光焊接设备,对板厚为16 mm的X52管线钢进行焊接,X射线探伤检测焊缝无裂纹,采用光学显微镜分析了焊接接头的焊缝结晶特性和微观组织。根据美国石油学会标准API SPEC 5L管线钢规范,对焊接接头进行了力学性能试验。结果表明:焊接接头的抗拉强度达480 MPa,断于母材;180°接头弯曲未出现裂纹;-20℃焊缝金属冲击韧性CVN=279 J,熔合区冲击韧性CVN=282 J,热影响区冲击韧性CVN=212 J,焊接接头的最大硬度分布在焊缝下部,为270 HV左右。研究表明,各项性能均满足管线钢焊接的要求。Welding is one of the key technologies in pipeline construction. The corresponding welding technology should be meeting the requirements of the pipeline construction due to the rapid development of advanced pipeline steel. The advantages and disadvantages of laser welding for pipeline steel are analyzed. X52 pipeline steels with a thickness of 16 mm are welded using high power CO2 laser. Cracks in the weld are not detected by X-ray. Solidification properties and microstructure of laser welded joint have been studied by optical microscope. The mechanical tests of the welded joint have been conducted according to American Petroleum Institute Specification API SPEC 5 L.The results show that the ultimate tensile strength is 480 MPa ,fracturing in parent metal,without any cracks in 180°bend specimens;and Charpy notch toughness at -20 ℃ is CVN=279 J in weld metal,CVN=282 J in fusion zone and CVN=212 J in heat affected zone. The maximum hardness of butt welded joint is about 270 HV,which locates in the bottom of weld. All the mechanical properties of weld produced by using laser welding can meet the welding technical requirements of X52 pipeline steel.

关 键 词：激光焊接 X52管线钢 微观组织 力学性能 显微硬度 

分 类 号：TG456.7[金属学及工艺—焊接]