换热管-管板四种组对坡口的焊接接头性能

选用氩弧焊工艺对10号钢换热管与16MnⅡ管板四种组对坡口形式(缩孔45°、缩孔U型、凸孔45°、平口45°)进行了焊接,并对其进行了拉伸及低周疲劳性能研究,对断后焊缝断面进行了显微形貌观察和微观组织分析。结果表明:四种组对坡口形式焊缝结合良好,无明显缺陷。缩孔和凸孔焊接试样拉伸性能相差不大,平口焊接试样略低;平口焊接试样抗疲劳性能优于凸孔焊和缩孔焊。因此四种组对坡口形式中平口焊接试样的接头性能最优。

TIG welding process was used to connect 10# steel tubes and 16Mn II tube sheet with four groove types (Retracted 45°, Retracted U shaped, convex 45°and lfat 45°). Tensile and low cycle fatigue testing were conducted. The microscopic morphology and microstructure of the cross section of rapture welds were analyzed. The experiment and analysis results show that four groove type welds connected well with no obvious defects. The tensile properties of welding specimens are almost the same. The fatigue properties of lfat welding specimens are better than that of the retracted and convex ones. Thus lfat welding specimens have the best performance among four types of groove joints.