氮氧联合过渡对GPCA-TIG焊焊缝的影响

针对外层引入氮氧混合气体的气体熔池耦合活性TIG焊,通过改变焊枪内外喷嘴的相对位置,分别研究了外层气体与熔池表面的耦合程度不同时焊缝成形、焊缝中氮氧含量及焊缝组织性能的变化规律.结果表明,氮氧联合过渡时气体熔池耦合活性TIG焊焊缝窄而深;低温冲击韧性高于母材及传统TIG焊的7.5%以上,而抗拉强度和屈服强度均略低于母材;焊缝组织晶粒细小,奥氏体上沿晶界分布着少量铁素体.气体熔池耦合活性TIG焊焊缝中的氮氧含量可以通过调节焊枪内外喷嘴的相对位置进行微量控制.

Effect of nitrogen in conjunction with oxygen on GPCA-TIG weld

For the gas pool coupled activating TIG (GPCA-TIG) welding with outer mixing shielding gas of nitrogen and oxygen, by changing the relative position of the outer and inner nozzles of welding torch, the effect of coupling degree between the outer shielding gas and welding pool surface on nitrogen-oxygen content in the weld appearance, microstructure and properties. The results show that the gas pool coupled activating TIG weld was narrow and deep when nitrogen was introduced in conjunction with oxygen. The low temperature impact toughness of weld was 7.5% higher than that of parent metal and weld made by traditional TIG welding, while the tensile strength and yield strength of weld by GPCA-TIG was lower than those of parent metal. The grains in the weld were fine, and a small amount of ferrites distributed in the austenite grain boundaries. The nitrogen-oxygen content in the weld could be finely adjusted through changing the relative position of outer and inner nozzles in GPCA-TIG welding.