Fatigue strength of welded joints of sus316l for chemical tankers

Welded joints in bulkheads made of SUS316L in chemical tankers frequently have cracks because of the lack of fatigue design data for the welded joints. In this study, the fatigue strength of the parent materials, the butt welded joints, and the transverse fillet welded joints made of SUS316L were investigated. Three types of conventional welding construction were adapted for the butt welded specimens in 17 and 20 mm thick plates. Three conventional combinations of welding and finishing were adapted for the transverse fillet welded specimens. The resulting fatigue performance was compared with that of the parent material and design data contained in the IIW Fatigue Design Recommendations For Steel. The fatigue strengths decreased in the order parent material, butt weld and fillet weld, with the corresponding S-N curves becoming gradually steeper with decrease in fatigue resistance. The S-N curves produced were all shallower, and they all indicated higher fatigue strengths than the IIW design curves.