Plasma Welding Defects and Its Preventive Measures
等离子焊接缺陷的产生及其防范措施

摘要

等离子弧焊能量集中，穿透力强，电弧柱刚直性好，小于等于8mm的钢板不需要开坡口，可有效进行单面焊双面成型焊接，焊接接头外观成形优良规整，且满足100% 射线探伤要求，提高了焊接效率，节约了生产成本，符合环保生产要求。因此，被广泛地应用于锅炉、压力容器、桥梁建筑、车辆船舶和航空航天等领域。但在中厚板焊接应用中，等离子弧焊接的工艺参数匹配区间窄，焊接过程会出现气孔、未熔合、未焊透、咬边、焊漏、焊瘤及穿孔不稳定等缺陷。有时在焊接一条较长焊缝的过程中时，甚至会出现焊接前段稳定，后段不稳定的情况，焊接重现性差。本文通过对等离子弧焊的技术原理的研究，结合生产实践，对等离子弧焊接出现的质量问题的成因进行了具体分析，提出了防范措施。

Abstract

the plasma arc welding energy concentration, strong penetrating power, arc column just good laymen, less than or equal to 8 mm steel plate does not need to open groove, which can effectively make one-side welding of forming welding, welding joint forming fine neat appearance, and satisfies the requirement of 100% radiographic, improve the welding efficiency, save the production cost, accord with environmental protection requirements of production. Therefore, it is widely used in boilers, pressure vessels, bridge construction, vehicles and ships and aerospace and other fields. However, in the application of medium and thick plate welding, the matching interval of process parameters of plasma arc welding is narrow, and there will be defects such as porosity, non-fusion, non-penetration, edge biting, welding leakage, welding nodulation and perforation instability in the welding process. Sometimes in the process of welding a long weld, there will even be stable welding front section, unstable back section, welding reproducibility is poor. Based on the research of the technical principle of plasma arc welding, combined with the production practice, the causes of the quality problems of plasma arc welding are analyzed, and the preventive measures are put forward.