Welding duplex stainless steels - A review of current recommendations

Abstract

A steel will not become widely accepted and used unless it can be successfully welded without too many limitations. Contemporary duplex stainless steel grades fulfill these requirements with some grade-dependent differences. The duplex stainless steel family has, during the last decade, been extended with new lean grades and recently also highly alloyed hyperduplex grades. Most welding recommendations are very similar to those of the 1990s. However, the introduction of new grades and the increased use of newer welding methods have somewhat changed the perception of what is possible. This paper discusses the state of the art and trends in welding of duplex stainless steels. It is based on input from the worldwide welding community, including users and producers of steel and welding consumables, as well as literature. In most cases, recommendations are there, but consensus variations reflecting differences in practices exist, in particular for newer steel grades where limits in, e.g., allowable energy inputs are less well documented.