自保护药芯焊丝半自动焊焊缝韧性离散性成因分析及控制

Cause Analysis and Control of Weld Toughness Discreteness for Self-shielded Flux Cored Wire Semiautomatic Welding

文章系统介绍了扩散氢含量、夹杂物形态和分布以及焊缝中的微观组织对焊缝韧性及其离散性的影响,阐明了链状M-A组织是影响焊缝韧性及其离散性的本质导因,并从焊接热输入量、盖面焊接方式、焊接材料的选择、高Cr高N b母材焊接及焊接工艺评定等方面提出了改善焊缝韧性及其离散性的控制措施。

The influences of the diffusible hydrogen content, the configuration and distribution ot inclusions as well as the weia microstructure on the welding joint impact toughness and its discreteness are studied, and the results are described systematically. The results show that the ＂chain＂ M-A （martensite/austenite） structure is the fundamental factor which affects the welding joint impact toughness and discreteness. Some recommendations are also proposed from different aspects to improve the welding joint impact toughness and its discreteness, including heat input, cosmetic welding, welding material selection, welding of base metal with high concentration of Cr and Nb, as well as welding procedure qualification.