DUPLEX STAINLESS STEEL, METHOD OF MAKING SUCH STEEL AND INDUSTRIAL ARTICLE MADE FROM THIS STEEL (VERSIONS) Russian patent published in 2006 - IPC C22C38/54 C21D6/00 

FIELD: metallurgy; duplex stainless steels and methods of making such steels.

SUBSTANCE: proposed duplex stainless steel contains the following components, mass-%: carbon, up to 0.06; chromium, from 15 no less than 19; nickel, from 1 no less than 2; manganese, from more than 2 to 3.75; nitrogen, from more than 0.12 to 0.35; silicon, up to 2; molybdenum, up to 1.5; copper, up to 0.5; cobalt, up to 0.2; phosphorus, up to 0.05; sulfur, up to 0.005; boron, up to 0.03; the remainder being iron and unintentional impurities. Proposed duplex stainless steel may be made in form of such industrial articles, as strips, merchant shapes, plates, sheets, castings, pipes or pipe lines. Proposed method of making such steel includes heat treatment to solid solution and cooling.

EFFECT: enhanced corrosion resistance, pitting crevice corrosion inclusive.

36 cl, 2 tbl