Hydrogen induced cracking (HIC), caused by H2S service, is generally only a concern on pressure vessels. However, current practice by most of the oil majors is to select tank materials which exhibit low hardness levels in the heat affect zone (HAZ) after welding. Generally the hardness levels...
The Canadian standard CSA G40.21 lists 260W, 300W and 350W grades. The properties of the 300W are Min. Yield = 300 MPa, and UTS = 450 MPa. I do not have an old copy of this standard, but suspect the grades 44W and 50W may be based on old designations i.e. UTS in kgf/mm².
