大厚度船用高强钢激光-电弧复合焊技术研究

为实现大厚度高强钢全熔透单道对接焊,针对厚度20mm的AH32船用高强钢,采用15kW大功率CO_2激光进行激光-电弧复合焊接.分析了工件坡口、焊接速度、送丝速度、离焦量、装配间隙等规范参数对焊缝成型影响;通过金相观察以及显微硬度测定分析了接头组织性能.结果表明:通过激光功率等焊接规范匹配,激光-电弧复合焊接能实现20mm厚板的全熔透单道对接;钝边为8mm的Y形坡口有助于提高厚板激光-电弧复合焊缝熔透能力;降低焊接速度有利于提高熔深能力;工件厚度较大时,装配间隙对焊缝熔深能力的影响较为显著;接头硬度表明厚板激光复合焊焊缝纵向热循环模式存在较大差异.

Research on Laser-arc Hybrid Welding Process of Thick Ship Plates

In order to realize full-penetration butt welding by single-path on thick high strength steel, the AH32 steel plate with thickness of 20 mm was laser-arc hybrid welded using 15 kW CO_2 laser. The effect of parameters such as weld groove, wire feed rate, welding speed, defocus length and gap weld formation was analyzed. The microstructure of joint was analyzed by metallographic obsveration and hardness test. The results show that laser-arc welding can achieve full penetration by single-path butt jointing through appropriate parameters; Y shape groove with 8 mm truncated edge can enhance the penetration ability of laser-arc hybrid welding. Low welding speed is good for penetration, however the limitation still exists for hick plates joint. Gap is significant factor of penetration when work pieces is large thickness. The hardness of thick plates joint shows that there is big difference in mold of vertical thermal cycle using laser-arc hybrid welding.