摘要
研究了20~#钢光纤激光焊接工艺对焊接质量的影响。研究发现,随着激光功率的增加,焊缝背面熔宽显著增加,焊缝由钉形向近X形转变,焊接过程中产生的飞溅增多;随着焊接速度的增加,焊缝变得"细小",焊缝正面咬边情况加重;离焦量在-2^+2mm范围内变化对焊缝形貌和焊缝熔宽的影响不明显,相较于在正离焦量和零离焦量下焊接,负离焦量时焊接过程中产生的飞溅较多。在所有实验设定的参数范围内,焊缝内部质量优良,无气孔、裂纹等缺陷,接头拉伸断裂位置均在母材,焊缝强度能够得到保证;焊缝区组织为板条状马氏体组织,硬度在440HV左右,远高于母材(约160HV)。
In this paper,influence of fiber laser welding process on welding quality of 20 steel was studied.It was found that with the increase of laser power,back weld width increased,and the joint from nail shape changed into near X shape,meanwhile the welding spatter increased.With the increase of welding speed,the seam became slender,undercut in front of weld increased at the same time.It was observed that the defocusing amount within the range of -2~＋2 mm had no significant effect on weld shape or width,while the welding spatter got worse as the defocusing amount was negative compared to those of positive and zero conditions.Within the set of experimental parameters,all joints showed excellent quality without holes or cracks.Tensile test showed that joints fractured at the base metal,and the microstructure of welding zone was the martensite structure,leading to a high hardness value of about 440 HV,which is much higher than that of the base metal of about 160 HV.
出处
《应用激光》
CSCD
北大核心
2017年第4期534-539,共6页
Applied Laser
