Stress corrosion cracking in steels in liquid Ammonia

Because Ammonia is a promising medium to transport and store hydrogen. liquid ammonia storage and transportation tanks are expected to increase in size. Ammonia stress corrosion cracking (SCC) poses a potential risk to storage tanks. Although research on ammonia SCC peaked in the 1970s–80s but has recently regained attention due to a potential cause of tank damage. This review compiled the key findings from previous studies to clarify the extent of knowledge regarding ammonia SCC. In addition to the experimental methods for assessing ammonia SCC susceptibility, this review focused on factors influencing the behavior of ammonia SCC. Previous studies also showed that the application of electrical manipulation to ammonia SCC and dependency of material hardness on susceptibility. However, the electrochemical reaction associated with film/scale formation and the effect of steel microstructures on ammonia SCC are unknown. This review discussed three critical topics: accelerated testing, ammonia SCC mechanisms, and preventive strategies.