Effect of the Microstructure on Strength properties of the Duplex Stainless Steel wire after Cold drawing and Aging

Abstract

Mechanical properties (work-hardening and age-hardening, rigidity modulus) of the duplex stainless steels composed of different austenitic stability were investigated. The relationship between their mechanical properties and metallography such as phase fractions, α/γ component distribution, crystal orientation was discussed. The tensile strength of SUS821L1 after cold drawing at a cross-sectional reduction of 75 % is about 230 MPa higher than that of SUS329J3L and satisfies the B type standard of spring stainless steel wire. The rigidity modulus of SUS821L1 after drawing and aging is about 85 GPa. It is about 10GPa higher than that of SUS329J3L. The main factor of the high strength and high rigidity modulus of SUS821L1 after drawing and aging is suggested by the deformation-induced martensite containing supersaturated nitrogen.