K-TIG焊接动态过程及组织和性能分析

为研究较高热导率材料的K-TIG焊接方法的焊接特性，采用K-TIG焊接技术对10 mm厚Q235钢进行了焊接.K-TIG焊接过程稳定，得到了焊缝成形良好，无裂纹、气孔等缺陷的焊接接头，通过高速摄影试验观察“匙孔”在焊接过程中的动态行为，并对焊接接头微观组织和硬度、拉伸、冲击、弯曲等力学性能进行了测试. 结果表明，改善散热条件和合理的装配间隙能增加K-TIG焊接“匙孔”的稳定性；焊缝区和热影响区的维氏硬度值均高于母材；焊接接头的抗拉强度、冲击韧性优于母材；焊缝区主要由细小的针状铁素体和少量的块状铁素体组成；K-TIG焊接方法在较高热导率材料领域的使用可行性得到证实，对低碳钢K-TIG焊接工艺的进一步研究具有一定参考意义.

Study on K-TIG welding process and properties of Q235 steel

The K-TIG welding technology was used to weld the 10 mm thick Q235 steel. The results showed that the welding process was stable, and the welded joint with good weld formation and no defects such as cracks and pores was obtained. The dynamic behavior of keyhole in the welding process was observed by high-speed photography test, and the microstructure and hardness of the welded joint were studied The mechanical properties such as tensile, impact and bending are tested. The results show that the stability of keyhole of K-TIG welding can be increased by improving the heat dissipation condition and reasonable assembly clearance; the Vickers hardness of weld area and heat affected area are higher than that of base metal; the tensile strength and impact toughness of welded joint are better than that of base metal; the weld area is mainly composed of fine acicular ferrite and a small amount of massive ferrite The K-TIG welding joint with excellent properties has been obtained, which has reference significance for the further study of K-TIG welding process of low carbon steel.