As defined in API RP 571, under Hydrogen Blistering and HIC/SOHIC:
“SOHIC typically manifests as subsurface stepwise cracking, generally oriented perpendicular to the direction of stress.”
“This mechanism initiates below the surface, typically in weld heat-affected zones, and requires metallographic or advanced ultrasonic methods to detect.”
By contrast, SSC, caustic cracking, and amine SCC are primarily surface-initiated, stress-related cracking mechanisms.
Thus, SOHIC is the subsurface mechanism in this list, making option D correct.
Contribute your Thoughts:
Chosen Answer:
This is a voting comment (?). You can switch to a simple comment. It is better to Upvote an existing comment if you don't have anything to add.
Submit