The clarification of the occurrence mechanism of creep micro cracking at weld joint based on vacancy diffusion analysis

Article type: Research Article

Authors: Ozeki, Go^{a; *} | Yokobori, A. Toshimitsu^a | Endo, Toshihiro^b | Sato, Fumio^b | Ohmi, Toshihito^c | Sato, Kazuto^d

Affiliations: [a] Teikyo University, 173-8605, Tokyo, Japan | [b] Tohoku Electric Power Company, 981-0952, Sendai, Japan | [c] Shonan Institute of Technology, 251-8511, Kanagawa, Japan | [d] Tohoku University, 980-8579, Sendai, Japan

Correspondence: [*] Corresponding author. E-mail: [email protected].

Abstract: Since high temperature creep condition was applied to thermal power plant components for long-term, it is important to evaluate the creep fracture life. Especially, the reduction of the creep strength at weld joint induced by micro creep cracking is important problem. The creep void initiation and growth under high temperature creep condition is considered to be caused by vacancy diffusion and concentration. Therefore, it is important to clarify the vacancy diffusion and concentration behavior. In this study, relationship between the site of stress concentration and the vacancy diffusion behavior at weld joint was analyzed using proposed two-dimensional stress induced vacancy diffusion analysis. And it was related to crack initiation at the weld joint.

Keywords: Creep, vacancy diffusion, weld joint, two-dimensional stress induced vacancy diffusion analysis

DOI: 10.3233/SFC-170204

Journal: Strength, Fracture and Complexity, vol. 10, no. 2, pp. 101-116, 2017