储罐9%Ni钢纵缝自动焊接技术应用分析

对比分析目前国内外大型LNG储罐内罐常见的焊接方式及储罐现状,介绍SMAW(Shielded Metal Arc Welding)、FCAW(Flux Cored Arc Welding)及TT焊(TIP-TIG)的优缺点。根据试验发现,TT焊工艺对9%Ni钢焊缝成型好,过渡圆滑、鱼鳞纹规则且余高较小,热影响区宽度小,枝晶分布均匀,焊丝(条)熔敷率高、坡口较多为U型,且通过已在东部沿海某试运行的LNG储罐可知,其试运行稳定,并已投入使用。

The common welding methods and current situation of large LNG storage tanks at home and abroad are compared and analyzed,and the advantages and disadvantages of SMAW(Shielded Metal Arc Welding),FCAW(Flux Cored Arc Welding)and TT(TIP-TIG)welding are introduced.According to the test,it is found that the TT welding process has good weld shape,smooth transition,regular fish scale pattern and small residual height,small width of HAZ and uniform dendrite distribution.The deposition rate of welding wire(rod)is high,and most of the grooves are U-shaped,and through a trial operation of a LNG storage tank along the eastern coast,its trial operation is stable and has been put into use.