Stress corrosion cracking susceptibilities of carbon steel and its welded joint in high temperature water

Abstract

This study was carried out in order to understand the behavior of Fan-shaped Pattern type Stress Corrosion Cracking (FSP-SCC) susceptibilities of carbon steel and its welded joints in pure water, simulating an LWR (Light Water Reactor) under high temperature and high pressure. The susceptibility of FSP-SCC was examined under various temperatures (373 to 573 K) and dissolved oxygen levels (0.007 to 8 ppm) as environmental factors using the Slow Strain Rate Tensile test (SSRT). An evaluation method for susceptibility of FSP-SCC using data obtained here, are discussed and then an optimized evaluation method is proposed. The SCC susceptibility at the welded joints were also investigated.

本研究は高温および高圧下でLWR(軽水炉)をシミュレートし、炭素鋼およびその溶接接合部の扇形状タイプの応力腐食割れ(FSP-SCC)感受性挙動を理解するために行った。FSP-SCCの低速度引張り試験(SSRT)を使い環境要因として溶存酸素レベル(0.007から8ppm)、種々の温度(373から573K)下で試験した。本研究で得られたデータを使いFSP-SCCの感受性に対する評価法について論じ、それから最適化された評価法を提案した。また溶接部のSCC感受性について調査した。