Stress-oriented hydrogen-induced cracking (SOHIC)

Thread Content

Stress-guided hydrogen-induced cracking refers to the cracking that occurs when small cracks formed due to hydrogen accumulation at inclusions or defects overlap and propagate in a direction perpendicular to the stress (i.e., in the thickness direction of the steel plate). Its typical feature is that the cracks propagate in a zigzag pattern. Some believe that it is also a special form of stress corrosion cracking (SCC). SOHIC also often occurs in the heat-affected zone of welds and other areas with high stress concentrations. Unlike SCC, SOHIC is more sensitive to inclusions present in the steel. Stress concentration is often caused by crack-like defects or stress corrosion cracks; it has been reported that the coexistence of SSCC and SOHIC has been observed in multiple cracking cases. Schematic diagram of stress-directed hydrogen-induced cracking