2025 Volume 74 Issue 6 Pages 113-116
A fracture mechanics evaluation of the initiation and propagation of stress corrosion cracking, SCC, in high-strength carbon steel plates, HT780, was performed using notched four-point bending test specimens at 2 V （vs. Pt） in liquid ammonia. A semi-elliptical SCC was obtained with a stress intensity factor, K, of 3.2 MPam0.5. Further tests using lower initial K-values and longer test periods are needed to verify whether this is the critical K-value, KISCC, or not. Although relationships between SCC growth rate and K were obtained, their SCC growth characteristics were significantly accelerated. It is necessary to reduce SCC acceleration and to understand the effects of SCC acceleration conditions on SCC growth characteristics for SCC growth prediction in the actual liquid ammonia tank environment.
