不同药芯焊丝工艺条件下X80管线钢焊缝组织与性能对比  

Comparison of microstructure and properties of X80 girth weld joints welded by different flux-cored wire process conditions

作　　者：王汉奎[1] 李阳 姚呈祥 李海舰 何仁洋[1] WANG Hankui;LI Yang;YAO Chengxiang;LI Haijian;HE Renyang(China Special Equipment Inspection and Research Institute,Beijing100029,China;PetroChina Changbei Natural Gas Central Processing Facility,Yulin719000,China)

机构地区：[1]中国特种设备检测研究院,北京100029 [2]中石油长北天然气处理厂,陕西榆林719000

出　　处：《压力容器》2024年第1期12-17,44,共7页Pressure Vessel Technology

基　　金：国家石油天然气管网集团有限公司科学研究与技术开发项目(GWHT20210040408);中国特种设备检测研究院项目(2020-内02)。

摘　　要：为保障管线安全、平稳运行,提高管线环焊缝的可靠性,对已经投用的2条X80管线环焊缝进行对比分析。2条X80管线的环焊缝的焊接方法为药芯焊丝自保护焊(FCAW-S)和药芯焊丝气保护焊(FCAW-G),对比分析了焊缝的化学成分、金相组织、硬度、拉伸强度和冲击韧性等方面。分析发现,2种焊接方法获得焊缝均比母材Ni含量高,Cr、Mo含量低;FCAW-S焊缝的Al、N含量远高于FCAW-G焊缝及母材。FCAW-S焊缝晶粒内,亚结构尺寸大、取向的多样性低。与FCAW-G焊缝相比,FCAW-S焊缝的硬度高,屈服强度低、抗拉强度较为接近。由系列冲击试验可见,FCAW-S焊缝的韧脆转变温度为12.2℃,比FCAW-G焊缝高55.6℃。据此推断相同条件下,采用FCAW-S焊接的环焊缝发生脆性断裂的概率大。In order to improve the reliability of the girth weld of the pipeline and ensure the safe and smooth operation,a comprehensive comparative analysis of the two X80 pipeline girth welds that have been put into use was conducted.The welding methods of the girth weld of the two X80 pipelines are flux-cored wire self-shielded welding(FCAW-S)and flux-cored wire gas shielded welding(FCAW-G),and the comparative analysis includes chemical composition,metallographic structure,hardness,tensile strength and Charpy impact test.The analysis shows that the weld metal had higher Ni and lower Cr and Mo than the base metal.The Al and N contents of FCAW-S weld are much higher than those of FCAW-G weld and base metal.In the grains of FCAW-S weld,the substructure size is large and the diversity of orientation is low.Compared with FCAW-G weld,the hardness of FCAW-S weld is higher,the yield strength is lower,and tensile strength is relatively close.It can be seen from a series of impact tests,the ductile-brittle transition temperature(DBTT)of FCAW-S weld is 12.2℃,which is 55.6℃higher than that of FCAW-G.From the test results,it is concluded that the girth weld welded by FCAW-S has a high possibility of brittle fracture.

关 键 词：X80管线 环焊缝 脆性断裂 焊缝性能 

分 类 号：TH49[机械工程—机械制造及自动化] TG406[金属学及工艺—焊接]