外层氧气引入对GPCA-TIG焊焊缝性能的影响

针对SUS304不锈钢，采用传统TIG焊和GPCA-TIG焊进行工件表面熔焊，对外层气体引入氧气的GPCA-TIG焊和传统TIG焊焊缝的氧含量、显微组织、拉伸性能和低温冲击韧性进行了测定. 结果表明，GPCA-TIG焊焊缝组织主要为奥氏体和铁素体，铁素体形态以骨架状和板条状为主. 外层引入氧气时，焊缝中的氧含量增加，耦合度为+2时焊缝中的氧含量高于耦合度为0时的，焊缝的抗拉强度均略低于母材的. 耦合度为0的GPCA-TIG焊焊缝冲击性能与传统TIG焊的相同，耦合度为+2的焊缝低温冲击韧性有所降低，达到传统TIG焊的85%.

Effects of oxygen outer gas on weld properties of gas pool coupled activating TIG welding

Based on SUS304 stainless steel, bead-on-plate experiments for both ordinary TIG welding and GPCA-TIG welding using O₂ as the outer gas were made to evaluate the oxygen content in the weld, micro-structure, the tensile properties and low temperature impact-toughness of the weld. The results show that, the weld micro-structure of GPCA-TIG welding mainly composites of austenite and ferrite. The morphology of ferrite is lacy and vermicular. Oxygen introduced as the outer gas makes the weld oxygen content increase. When the coupling degree is +2, the weld oxygen content is higher than that of coupling degree 0. The tensile strengths of the weld are all slight lower than those of the parent metal. The low temperature impact-toughness of the weld with coupling degree 0 is almost the same with that of TIG welding, while the low temperature impact-toughness value for coupling degree +2 is decreased and only reaches 85% of traditional TIG welding.