Anneal effect of internal strain in dissimilar materials by laser welding

Shobu, Takahisa  ; Zhang, S.; Shiro, Ayumi; Muramatsu, Toshiharu; Yamada, Tomonori; Kono, Fumiaki; Ozawa, Takayuki   

In order to clarify an anneal effect of internal strain in dissimilar materials by laser welding, internal strain measurements using high energy synchrotron white X-rays were carried out at BL14B1 in SPring-8. The specimens were dissimilar materials made by laser welding between ferritic/martensitic steel (PNC-FMS) and SUS316 austenitic stainless steel. In this study, we measured the internal strain distribution of three kinds of specimens which changed a laser irradiation condition and it was found that the tensile strain in ferritic/martensitic steel occurred in all specimens before annealing but the residual strain in austenitic stainless steel was not so remarkable. It is thought that these reasons are related to the mechanical characteristic of both the materials. On the other hand, in all specimens after annealing, it was found that the residual strain in both the materials did not almost exist.