9%Ni钢制LNG储罐纵缝自动热丝TIG与SMAW对比研究  

Comparative study on automatic hot wire TIG and SMAW for longitudinal seam of 9%Ni steel LNG storage tank

作　　者：李雪梅 LI Xuemei(Sinopec Fourth Construction Co.,Ltd.,Tianjin 300270,China)

机构地区：[1]中石化第四建设有限公司,天津300270

出　　处：《压力容器》2024年第12期67-74,共8页Pressure Vessel Technology

基　　金：中国石化集团公司科技开发项目(322017)。

摘　　要：针对9%Ni钢制LNG储罐纵缝采用传统的焊条电弧焊(SMAW)焊接效率低、打磨工作量大、造成罐内焊接环境差的问题,提出窄坡口自动热丝钨极氩弧焊(自动热丝TIG)进行纵缝焊接的工艺技术,采用储罐最薄10 mm和最厚32 mm的9%Ni钢板进行了对比试验,并分析了自动热丝TIG与传统SMAW的焊接工艺、焊接成形、焊接接头的力学性能。通过两种方法对比分析,结果表明,窄坡口自动热丝TIG焊接效率高,约为SMAW的2倍;力学性能更优,其中,焊缝区-196℃KV2约为SMAW的2倍,焊缝组织晶粒度更加细小;外观质量好;无需道间清理及焊道最终的打磨处理,减少粉尘产生,改善了罐内作业环境。该窄坡口自动热丝TIG工艺技术可在LNG储罐内罐纵缝推广应用。To address the inefficiency,excessive grinding workload,and poor welding environment caused by traditional shielded metal arc welding(SMAW)for longitudinal seams of 9%Ni steel LNG storage tanks,this study proposes a narrow-gap automatic hot-wire tungsten inert gas(TIG)welding process.Comparative experiments were conducted using 9%Ni steel plates with thicknesses ranging from 10 mm(minimum)to 32 mm(maximum)to analyze the welding procedures,weld formation,and mechanical properties of joints produced by automatic hot-wire TIG and SMAW.Results indicate that the narrow-gap automatic hot-wire TIG welding significantly outperforms SMAW,achieving approximately double the welding efficiency and exhibiting superior mechanical properties,including a Charpy V-notch impact energy(KV2)at-196℃in the weld zone nearly twice that of SMAW,along with finer grain structure.Additionally,the process eliminates inter-pass cleaning and final grinding,thereby reducing dust generation and improving the internal tank working environment.This automated hot-wire TIG process demonstrates strong potential for widespread application in longitudinal seam welding of LNG storage tank inner vessels.

关 键 词：LNG储罐 9%NI钢 自动热丝TIG 焊条电弧焊 

分 类 号：TH142[一般工业技术—材料科学与工程] TG44[机械工程—机械制造及自动化]