Investigation of the Mechanism of IGA/SCC of Alloy 600 in Corrosion Accelerating Heated Crevice Environments. Technical Progress Report Fourth Quarter. Nuclear Energy Research Initiative (NERI) Program.

Lumsden, J.

Technical Information Center Oak Ridge Tennessee

关键词: Stress corrosion;    PWR type reactors;    Inconel 600;    Steam generators;    Crack propagation;   

RP-ID  :  DE2002765749

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

This program focuses on understanding mechanisms causing corrosion damage to steam generator tubes in a pressurized water reactor (PWR). The crevice formed by the tube/tube support plate (T/TSP) intersection in a PWR steam generator is a concentration site for nonvolatile impurities (referred to as hideout) from the steam generator water. The restricted mass transport in the small crevice volume prevents the species, which concentrate during the generation of steam, from quickly dispersing into the bulk water. The concentrated solutions in crevices have been a contributing cause of several forms of corrosion of steam generator tubes including intergranular attack/stress corrosion cracking (IGA/SCC), pitting, and wastage (general corrosion of the tube). The rate and type of corrosion are dependent on pH, specific anions, and the electrochemical potential (ECP). A key variable is the ECP since the type and kinetics of corrosion processes are determined by the potential.