New Materials and Forgings Used for Pressure Vessels Operating in Hydrogen Environment

摘要

To improve the in-service behaviour of Cr Mo (V) steel grades used for the pressure vessels operating in hydrogen environment at high temperature for the oil industry, the manufacture of heavy forgings needs a high quality. Improvement of the standard and enhanced strength (ASME Case 1960) 2 1/4 Cr 1 Mo steel grades may be achieved by reducing drastically the impurities (S, P, X-bar, etc ...) to extra low level and avoiding segregates at the inner surface of the shells. For high temperature operation, new V modified steel grades are proposed (ASME case 1961, Code Case 1973 and Code Case 2098). Their conventional mechanical properties are similar to those of enhanced strength 2 1/4 Cr 1 Mo but they offer higher creep properties and improved resistance to hydrogen damage.