Duplex Stainless Steel: Metallurgy, engineering codes & welding practices (Part 2 of 2)

摘要

Duplex stainless steels are synonymous with extremely demanding service applications. These alloys offer a combination of good corrosion resistance, resistance to stress corrosion cracking in various service media, with good mechanical properties. These steels are frequently used in the oil and gas industries (and chemicals/petrochemical industries) both in upstream and downstream applications for components, e.g. pressure vessels, exchangers, pipe work systems, manifolds and risers, valve and other applications. Although duplex stainless steels in many cases are superior in corrosion resistance and strength compared to 304 and 316 austenitic stainless steels, many fabricators continue to have difficulties creating welding procedures that yield repeatable weldments with optimum properties. This paper offers an overview of the issues involved in achieving high integrity, high quality, duplex stainless steel weldments.