921A钢水下激光填丝焊接工艺研究

Study on unde rwater laser wire filling welding procedure of 921A steel

采用激光填丝焊接方式,以16mm厚度的921A船用钢为母材,选择不同的焊接参数及焊接环境进行对比工艺试验,并对焊缝进行了金相分析,研究激光离焦量、湿式水深、环境压力等主要焊接参数对焊接质量的影响规律。结果表明:焊缝的熔深、熔宽随环境压力的增加逐渐减小,焊缝堆高随压力增加而略有减小。湿式水深4 mm下的焊缝比较平滑,无明显外观缺陷;水深增加到5mm后,焊缝均匀性变差;当水深增加到7mm时,焊缝成形困难,基体表面仅有烧灼痕迹。熔宽具有随离焦量增加先减小再逐渐趋于平稳的趋势、熔深具有随离焦量增加逐渐减小趋势,在离焦量为20 mm左右时焊缝成形最好。

Laser wire filling welding method is used with different welding parameters and welding environments by using16 mm thick 921 A marine steel as the base metal.The metallographic analysis and mechanical property test are carried out for the weld.The influence of the main welding parameters such as laser defocusing distance,wet water depth,environm-ental pressure and welding speed on the welding quality are studied.The results show that the depth and width of penetration reduce gradually as the environmental pressure increases,and the weld height decreases slightly as the pressure increase.When the water depth is within 4 mm,the weld is relatively smooth without obvious appearance defects;when the water depth increases to 5 mm,the uniformity of the weld becomes poor;when the water depth increases to 7 mm,the weld is difficult to form,and there are only burn marks on the surface of the base metal.The width of penetration decreases first and then stabilizes gradually as the defocusing distance increases.The depth of penetration reduces gradually as the defocusing distance increases.The appearance of weld is best when defocusing distance is about 20 mm.