Abstract
In order to clarify the thermal fatigue life of welded austenitic (SUS 316) ferritic (2.25 Cr-1 Mo) transition joints, the stress and strain behaviors near the weld interface of the joints were analysed by numerical inelastic analysis. The fundamental life relationships of creep rupture and fatigue strength were obtained by using uniaxial test specimens prepared from the joints. Then the lives of the joints were estimated on the basis of the creep-fatigue linear damage rule. The results are summarized as follows.
(1) The single bevel grooved butt joint with austenitic (JIS D309) weld metal has a slightly shorter life than the single-Vee grooved butt joint with the same weld metal.
(2) The single-Vee grooved butt joint with ferritic buttered layer and austenitic weld metal has a life 1.5 times that of the same joint with only austenitic weld metal.
(3) The single-Vee grooved butt joint with Incone type (JIS DNiCrFe) weld metal has a life 7 times that of the same joint with austenitic weld metal.
