“…The deformation characteristic (stress-strain relation) is dependent on the material, and its influence on failure prediction has not been thoroughly discussed in previous studies. The assessment criteria were based on the elastic shell theory [4], and most of the previous studies were focused on such line pipe steel as X52 [10], X60 [1][10], X65 [10] [11], and X80 [12] of the API standards. Conversely, in nuclear power plants, various materials are used in the piping systems and wall-thinning has occurred not only in carbon steel pipes but also in stainless steel pipes (e.g., at the Onagawa nuclear power plant, in May 2006).…”