Failure Assessment and Strength of Steam Generator Tubes with Wall Thinning

J. Ocean Eng. Technol. 2007;21(2):50-59.

Seong, Ki-Yong;Ahn, Seok-Hwan;Yoon, Ja-Moon;Nam, Ki-Woo;

Department of UR Interdisciplinary Program of Mechanical Engineering Graduate School, Pukyong National University;School of Mechanical Engineering, Pukyong National University;Department of Energy & Safety Engineering, Yokohama National University;Divisio

증기발생기 전열관 감육부의 강도 및 손상평가

성기용;안석환;윤자문;남기우;

부경대학교 대학원 기계공학학연협동과정;부경대학교 기계공학부;요코하마국립대학 물질공학과;부경대학교 신소재공학부;

Keywords: Steam generator tube, Wall thinning, Inconel, Bending load, Finite element analysis, Strength, Deformation

핵심용어: 증기발생기 전열관, 감육, 인코넬, 굽힘하중, 유한요소해석, 강도, 변형

Abstract

Steam generator tubes are degraded from wear, stress corrosion cracking, rupture and fatigue and so on. Therefore, the failure assessment of steam generator tube is very important for the integrity of energy plants. In the steam generator tubes, sometimes, the local wall thinning may result from severe degradations such as erosion-corrosion damage and wear due to vibration. In this paper, the elasto-plastic analysis was performed by FE code ANSYS on steam generator tubes with wall thinning. Also, the four-point bending tests were performed on the wall thinned specimens, and then it was compared with the analysis results. We evaluated the failure mode, fracture strength and fracture behavior from the experiment and FE analysis. Also, it was possible to predict the crack initiation point by estimating true fracture ductility under multi-axial stress conditions at the center of the thinned area from FE analysis.