电弧功率对Laser+GMAW-P复合热源焊热场特征的影响

EFFECT OF ARC POWER ON THERMAL FIELD CHARACTERISTICS OF LASER+GMAW-P HYBRID WELDING

焊接HAZ的热场特征,如HAZ的宽度和焊接热循环的参数等,对焊接接头的组织和性能有重要影响,是决定焊接接头质量的关键因素.本文应用已建立的复合热源焊的组合式体积热源模型,对Laser+GMAW-P复合热源焊的热场进行数值分析,定量研究了不同电弧功率对Laser+GMAW-P复合热源焊热影响区(HAZ)宽度和热循环参数等热场特征基础数据的影响规律,并与单激光焊和单GMAW-P焊的情况进行了比较,以期从冶金上揭示复合热源焊的特点.

Laser ＋ GMAW P （pulsed gas metal arc welding） hybrid welding is a combination of laser welding with GMAW-P which can not only bring the advantages of heatsources used in these two welding processes into full play, but also compensate for each other＇s drawback. Therefore, laser ＋ GMAW-P hybrid welding is a promising joining technology for industrial applications. With its applications becoming more widespread, there is a growing need to understand more deeply of this new welding process, such as the relationship between process parameters and weld quality. As the key factors determining weld quality, the thermal field characteristics of HAZ （heat affected zone） in welding, such as HAZ width and thermal cycle parameters, have significant effects on the microstructure and properties of welded joint. In this paper, an adaptive combined heat source model developed for laser ＋ GMAW-P hybrid welding was employed to conduct the numerical analysis of thermal field in hybrid welding. The influence of different arc power levels on the HAZ width and thermal cycle parameters in hybrid welding is quantitatively analyzed, and the relevant data obtained respectively during single laser welding, single GMAW-P and laser ＋ GMAW-P hybrid welding are compared to each other. It has been found that the HAZ width is less in hybrid welding than in GMAW-P even if the power input of laser ＋ GMAW-P hybrid welding is 2 kW larger than that of GMAW-P. When the arc power is lower, there is a small difference of HAZ width between GMAW P and laser ＋ GMAW- P, while the difference is narrowed down when the are power becomes higher. Laser ＋ GMAW-P hybrid welding causes a larger cooling time and lower peak temperature which are benificial to the improvement of microstruture and properties of HAZ. The results are very useful for demonstrating the process features and understanding more deeply the a.dvantages of hvbrid welding.