采用激光-MAG(Metal active gas arc welding)复合焊接工艺,以焊缝表面成形、焊缝纵截面形貌和熔深波动程度为工艺稳定性评价依据,借助高速摄像系统和图像处理方法,对焊接过程中飞溅和等离子体两种关键过程信息进行特征识别和定量化表征,系统地研究激光功率从 5kW提高到 30 kW时,焊接过程关键特征信息与焊接过程稳定性之间的关系.结果表明,随着激光功率的增加,焊缝表面成形出现周期性"上凸-下凹"现象,焊缝内部裂纹和熔深变化特征也随之周期性变化;等离子体面积和飞溅面积均随激光功率的提高呈增加趋势,且两者波动程度和熔深波动程度均呈正相关;等离子体面积增加会导致激光传输过程中能量衰减程度的加剧,使焊缝熔深增加趋势逐渐变缓,其波动程度是影响焊接过程稳定性的关键因素之一.
Forming stability of high power laser-MAG hybrid welding
Laser-MAG(Metal active gas arc welding)hybrid welding process was adopted.Based on surface appearance of weld,longitudinal section morphology and penetration fluctuation degree of weld,high-speed camera system and image processing method were used to characterize and quantify two key process information,spatter and plasma in welding process.Relationship between key characteristics and stability of welding process was systematically studied when laser power was increased from 5 kW to 30 kW.The results showed that with the increase of laser power,surface appearance of weld appeared a periodic"convex-concave"phenomenon,and internal cracks and penetration of weld also changed periodically.With the increase of laser power,both plasma area and spatter area increased,and whose fluctuation degree and penetration fluctuation degree were all positively correlated.The increase of plasma area would lead to intensification of energy attenuation during laser transmission,and the increase trend of weld penetration would gradually slow down,whose fluctuation degree was one of the key factors affecting stability of welding process.
high power laserlaser-MAG hybrid weldingplasmaspatterstability of welding process
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