Development of a new stainless austenitic CrMnNi steel using TRIP/TWIP effect for a high cold formability

Abstract

AbstractA new austenitic stainless CrMnNi steel with a high cold formability coupled with high strength was developed. The cold formability is based on the distinct transformation induced plasticity (TRIP) and twinning induced plasticity (TWIP). Thereby a maximum of strain is reached nearby room temperature. Using the TRIP/TWIP effect of CrMnNi steel a cost‐ and energy‐efficient production of thin sheets is enabled by a reduced number of interstage annealing. Thin sheets with thicknesses from 0.1 mm till 1.25 mm were cold‐rolled industrially and there properties compared to conventional CrNi steel 1.4301 (AISI 304) and CrNiMo steel 1.4404 (AISI 316 L).Plate and lamellae heat exchangers of CrMnNi thin sheets were produced under industrial conditions. The form stability of the plate heat exchangers was increased by 47 % and the component failure pressure raised by 45 % at room temperature. Based on its high strength it is suggested to apply the new austenitic CrMnNi steel in lightweight constructions. Although the nickel content was reduced by 50 % to 65 % compared to conventional steels 1.4301 and 1.4404 the corrosion resistance of the CrMnNi steel is comparable with conventional CrNiMo steel 1.4404.