Effects of Hydrogen Water Chemistry on Stress Corrosion Cracking Behavior of Cold-Worked 304L Stainless Steel in High-Temperature Water Environments

This study measured the stress corrosion cracking (SCC) growth rates of cold-worked 304L stainless steel in oxygenated and hydrogenated coolant environments. The effects of cold work at the levels of 5, 20, and 30% on SCC were also investigated. The SCC crack growth rate increased substantially with increases in the degree of cold work in oxygenated water environment. However, after hydrogen injection, SCC propagation in all cold worked specimens was gradually inhibited. The time to crack arrest decreased with increases in the degree of cold work. The slip bands caused by cold work facilitated the initiation and growth of transgranular (TG) cracks in specimens exposed to an oxygenated coolant environment. TG cracks were easier to arrest compared with intergranular cracks after the injection of hydrogen into the coolant system.