Q345碳钢超高功率激光切割工艺研究

Research on Ultra-High Power Laser Cutting Process of Q345 Carbon Steel

采用高功率光纤激光对20 mm厚Q345碳钢进行激光切割的工艺探究并观察切割后的重铸层和热影响区的微观组织。采用多组单因素实验,对比研究了激光功率、切割速度、辅助气体压力、离焦量对切割质量的影响规律,最佳工艺参数为激光功率8 kW、切割速度0.6 m/min、离焦量+10 mm、氧气辅助压力140 kPa、喷嘴直径1.4 mm、切割高度0.5 mm。通过SEM观察了切割后碳钢样品横截面的微观形貌,发现了重铸层及热影响区与基材之间微观组织形态与尺寸的差异,并分析了重铸层及热影响区微观组织的形成机理。研究成果有助于超高功率光纤激光切割技术在中厚钢板切割领域应用的推广。

The process of laser cutting 20 mm thick Q345 carbon steel with high power fiber laser was used to investigate and observe the microstructure of the recast layer and heat affected zone after cutting. The effects of laser power, cutting speed, auxiliary gas pressure, and defocus amount on cutting quality were compared using multiple sets of single-factor experiments. The optimal process parameters in this study were laser power 8 kW, cutting speed 0.6 m/min, Defocus amount +10 mm, oxygen assist pressure 140 kPa, nozzle diameter 1.4 mm, cutting height 0.5 mm. The morphology of the cross-section of the cut carbon steel samples was observed by SEM. The differences in microstructure and size between the recast layer and the heat affected zone and the substrate were found. The formation mechanism of the microstructure in the recast layer and the heat affected zone was analyzed. This research is helpful for the promotion of the application of ultra-high power fiber laser cutting technology in the field of cutting medium and thick steel plates.