燃料电池316L不锈钢极板的激光焊接工艺可靠性研究

Reliability Research on the Laser Welding Process of 316L Stainless Steel Pole Plate of Fuel Cell Summary

激光焊接具有焊缝小、质量高、密封性好、效率高、工艺成本低、容易实现自动化等优点,是批量生产双极板过程中最具潜力的工艺。在激光焊接过程中需要保证上下极板的焊接区域无间隙紧密贴合,以保证热量的正常传输,如果出现间隙产生空气层阻隔,则容易出现虚焊问题;在确保没有装配间隙的前提下,焊接过程中焊接路径、焊接功率、焊接速度、离焦量对焊接效果和成品率都有一定的影响。利用各种软件仿真结合实际测试检验,分析了316L不锈钢板在激光焊接时的热变形趋势,证明随着激光的热输入,停留时间的增加,极板在焊接中会出现越来越大的热变形,其可靠性急剧下降;结合极板的成型情况纠偏,可以利用电磁压紧工装进行矫正。

Laser welding has the advantages of small weld,high quality,good sealing-proprety,highefficiency,low process cost,and easy automation.It is the most potential process in the mass production of bipolar plates.During the laser welding process,it is necessary to ensure that the welding areas of the upper and lower plates are closely fitted withoutgaps to ensure the normal transmission of heat.If there is an air layer barrier in the gap,the problem of pseudo soldering will easily occur;on the premise of ensuring that there isno welding gap,During the welding process,the welding path,welding power,welding speed,and defocusing amount all have a certain influence on the welding effect and yield.Using various software simulations combined with actual test and inspection,the thermal deformation trend of 316L stainless steel plate during laser welding is analyzed and proved that with the heat input of the laser and the increase of the residence time,the plate will appear more and more thermal deformation during welding.This will make its reliability drop dramatically;The deviation can be corrected according to the forming situation of the pole plate,and the electromagnetic pressing tool can be used for correction.