本文介绍了采用廉价的氮氢混合气代替昂贵的氩气充入不锈钢管内部作焊缝背面保护气进行焊接的试验研究。通过机械性能、x光探伤、焊缝中氮与氢气含量、晶间腐蚀倾向、应力腐蚀敏感性、应力腐蚀断口电镜扫描、透射电镜对晶间碳化物进行电子衍射分析等测试表明,氮气中加入15％氢作背面保护,其焊接质量与纯氩保护的效果相同。成本至少降低三分之二。 This paper presents an experimental study of using cheap nitrogen-hydrogen mixed gas instead of expensive argon gas to fill the interior of a stainless steel tube for welding on the back of the weld gas. Through the mechanical properties, x-ray flaw detection, weld nitrogen and hydrogen content, intergranular corrosion tendencies, stress corrosion susceptibility, stress corrosion fracture scanning electron microscopy electron microscopy of intergranular carbide diffraction and other tests showed that the addition of nitrogen 15% hydrogen for back protection, the welding quality and the same effect of pure argon protection. Reduce costs by at least two thirds.