In uncertain times, duplex retains its lustre: Fid-Bau Portal

In uncertain times, duplex retains its lustre

Chater, James

Duplex stainless steels are receiving increased consideration from manufacturers and are being specified in an ever-broadening range of applications. This paper outlines the most important developments in the market place in the last year: company news, new products and new or growing markets. When it comes to materials selection, end users have become increasingly conscious of the need to keep initial expense as low as possible, but they are also wary of incurring excessive life cycle costs. Both considerations play to the advantage of duplex stainless steels. Not only can these often replace austenitics and highly alloyed materials at a cost that is considerably lower after weight and volume savings have been factored in; they have the added advantage of being resistant to stress corrosion cracking, which can reduce unscheduled downtime and repairs. Concerning investments, in the last year alone, NSSC, Acerinox and IPP have all announced they will increase their duplex output. Duplex is gaining market share in a number of applications in industries such as oil & gas, chemical, including chemical tankers and pulp & paper, where stress corrosion cracking (SCC) is always a worry, and in such areas as architecture, transport, storage tanks, where not only corrosion but yield strength is a factor. Oil & gas is the most established sector for duplex, and some important deals have been signed recently. Some of the new applications of Duplex steels in these areas are presented, showing that duplex grades are now proving competitive with ferritics as well as with austenitics is surely significant. It suggests that duplex grades will continue to make inroads into areas traditionally regarded as the domain of other grades for many years to come.