The small diameter steel pipe was welded by the technique of the full circumference pulse TIG welding, using the procedure of the backing TIG welding and filler rod TIG welding.

• 采用全位置脉冲TIG焊技术对小口径钢管环缝进行焊接,焊接采用TIG焊打底+TIG填丝的多层焊工艺,分析了打底焊及每层填丝焊接完成后的打底层焊缝组织。