活性硫对高功率激光焊接焊缝成形的影响

Effects of active sulfur powder on weld formation during high power laser welding

关键词:  激光焊接|活性硫粉|焊缝成形|金相组织

Key words:  laser welding|active sulfur powder|weld formation|metallographic structure

摘要:

文中试验研究了在万瓦级高功率光纤激光焊接厚板过程中添加表面活性硫粉对焊缝成形的影响及对焊缝微观组织的影响. 结果表明，表面活性硫粉的添加增加了熔池的浸润性和流动性从而形成了更长的焊接熔池. 负离焦焊接时，活性硫粉能增加焊缝熔深，且不受焊接速度的影响；而正离焦焊接时活性硫粉能增加焊缝熔宽. 高功率激光焊接过程能细化焊缝金相组织，且促使焊缝中铁素体比重增加；硫粉的添加则进一步促进了焊缝金相组织的细化及铁素体比重的增加.

Abstract:

The present work has been done to study the effects of surface-active sulfur powder on weld formation and weld microstructure during 10 kW-level high power fiber laser welding of thick plate. Observed results show that the surface-active sulfur powder increased the fluidity of molten metal and then the molten pool was elongated. When the defocused distance was negative, the active sulfur powder could increase the weld penetration and this influencing rule would not change under different welding speeds. When the defocused distance was positive, the active sulfur powder could increase the weld width. High power laser welding process could refine the grain size of weld and increase the ferrite proportion in weld. The added sulfur powder could refine the grain size and increase the ferrite proportion further.