The Effect of Plastic Deformation on Structural Integrity of Austenite-Ferrite Welded Joint

Abstract

Structural integrity is the science and technology of the margin between safety and disaster. Cata-strophic failure of any structure can be avoided if structural integrity is assessed and necessary precau-tion is taken. In this research structural integrity assessment of welded joints is studied both numerical-ly and experimentally. The application of fracture mechanics depends on available data, material behavior, environmental effect and loading. In predominantly static loading material behavior can be described as elastic-plastic, with crack opening displacement (COD) or the J integral as parameters. The theoretical and experimental analyses cannot fully describe the behavior of the cracked welded joint and its heterogeneous microstructure. For that purpose, the numerical analysis can be helpful, if applied in a proper way. An example of the finite elements numerical analysis of welded joints is pre-sented. It has been shown that previous plastic deformation of the base metal has detrimental effect on structural integrity of a pressure vessel.