直缝不锈钢焊管焊缝组织性能研究

Study on Weld Microstructure and Properties of Straight Seam Stainless Steel Pipe

针对等离子焊接直缝不锈钢管出现的咬边、气孔等焊缝表面成形缺陷,提出等离子+TIG双枪焊接新工艺,并对焊接接头进行X射线探伤检测、显微组织分析及力学性能测试。试验结果表明:等离子+TIG双枪焊接中,双枪具有协同效应。TIG电弧对前一焊道进行了重熔,有效抑制了等离子焊接缺陷的产生;直缝不锈钢管各项性能满足生产要求。准114 mm×3.0 mm的AISI304不锈钢在获得良好焊缝成形的条件下,采用等离子+TIG双枪焊接工艺的焊接速度可以达到360 mm/min;与等离子焊接工艺相比,生产效率大大提高,基本实现焊缝零缺陷。

Aiming at that the straight weld stainless steel pipe produced by plasma arc welding （PAW） had weld surface forming defects such as undercut and pores, the twin-gun PAW＋TIG welding process was proposed. The X - ray inspection, microstructure analysis and mechanical properties test of welded joints were carried out. The experimental results show that during the twin-gun PAW＋TIG welding, the two grins have synergies for the joints. The TIG arc follows the plasma arc and remelts the front seam formed by PAW, which effectively inhibits the formation of PAW defects. The performance of the straight seam stainless steel pipe can meet the production requirements. Under the conditions that the AISI304 stainless steel pipe with a specification of Ф114 mm×3.0 mm obtains good appearance, the welding speed by twin-gun PAW ＋TIG welding can reach up to 360 mm/min. Compared with PAW, the twin-gun PAW＋TIG welding can highly improve production efficiency and it basically accomplishes no defects of straight seam stainless steel pipe.