Austenoferritic stainless steel having a very low nickel content and a high tensile elongation

Abstract

An austenoferritic stainless steel with high tensile elongation includes iron and the following elements in the indicated weight amounts based on total weight: carbon<0.04% 0.4%<silicon<1.2% 2%<manganese<4% 0.1%<nickel<1% 18%<chromium<22% 0.05%<copper<4% sulfur<0.03% phosphorus<0.1% 0.1%<nitrogen<0.3% molybdenum<3% the steel having a two-phase structure of austenite and ferrite and comprising between 30% and 70% of austenite, wherein Creq=Cr %+Mo %+1.5 Si % Nieq=Ni %+0.33 Cu %+0.5 Mn %+30 C %+30 N % and Creq/Nieq is from 2.3 to 2.75, and wherein IM=551-805(C+N)%--8.52 Si %--8.57 Mn %--12.51 Cr %--36 Ni %--34.5 Cu %--14 Mo %, IM being from 40 to 115.

Dependencies are inferred from the claim text.