Additional Recommendations for Welding Cr-Mo-V Steels for Petrochemical Applications

The scope of this paper is the welding of high temperature creep resistant 2 1/4Cr-1Mo-1/4V steels for heavy wall pressure vessels for hydrogen service (petrochemical applications), plates such as ASME SA 542-D Cl4a, SA832 Gr 22V and forgings such as ASME SA 336 F22V, SA 182 F22V. Welding of these steel grades is widely covered by standards and codes, especially by API Recommended Practice P 934-A. The aim of this paper is to provide additional recommendations, applicable to submerged arc welding, in order to ensure sound welds and satisfactory service properties of welded joints. Parameters such as, selection of flux/wire combination, re-baking of flux, welding heat input, ISR and PWHT setting and monitoring, are of primary importance. In the present paper, recommendations concerning these parameters will be given, on the basis of our experience.