Mixed mode notch-crack fatigue propagation in the welding zone of 06Cr19Ni10 austenitic stainless steel: Effect of strain strengthening

Abstract

AbstractIn this work, mixed mode fatigue crack propagation in the welding zone of 06Cr19Ni10 austenitic stainless steel was experimentally investigated. The effects of strain strengthening on crack growth paths and growth rates were studied. The experimental results demonstrated that a new crack initiated from the notch-crack tip and propagated in the direction perpendicular to the loading direction, suggesting a change of the crack mode from mixed mode to Mode I. Strain strengthening has no effect on the crack growth paths, while it does have some effect on the crack growth rates. The metallographic results indicate that the fraction of transformed martensite increases with strain-strengthening level. Finite element analysis results reveal that strain strengthening can significantly change the distribution of the residual welding stress.