Abstract
It was found that the characteristics of welding distortion and residual stress generated by laser beam welding had the same tendency as ones by arc welding but that the absolute value was totally small. Moreover, nevertheless the process of laser beam welding is quite different from that of arc welding, the validity and generality of the dominant factors to predict high accuracy welding distortion and residual stress generated by welding could be verified by the high accurate prediction of welding distortion and residual stress which had been proposed base on arc welding. Inherent force was proposed as a parameter which could indicate the magnitude of compressive residual stress, which might influence the load-carrying capacity. Although inherent forces with laser beam welding was 40% that of arc welding, it was found that control of welding heat input was important so as to improve the load-carrying capacity.
