Cold rolling performance for austenitic stainless steel with equilibrium and non-equilibrium microstructures

Abstract

Aiming to provide effective theoretical guidance for continuous rolling, the cold rolling with reduction of 45% was carried out for the equilibrium and non-equilibrium microstructures of austenitic stainless steel (ASS). The microstructural evolution, texture components and tensile properties were investigated. The results showed that the fraction of martensite transformed from austenite is 21.1% for the equilibrium base metal (BM), while that for the non-equilibrium weld metal (WM) achieves 32.0%. Whether employing rolling or not, the fraction of misorientation larger than 15° within the BM is much higher than that of the WM because of the large amount of twins. Moreover, the texture of the rolled BM is mainly composed of Goss component with small amount of S and Brass, while that of the WM is composed of mainly S and small amount of Brass, with formation of Copper component. The tensile strength of the rolled BM and WM reaches approximately 1300 MPa, the elongation rate of the BM decreases from 53% to 5.7%, while that of the WM decreases from 32% to 3.5%. The microstructure evolutions of the BM and WM during rolling were compared, and the microstructure-mechanical properties relation was established and discussed based on martensitic nucleation. Keywords: Austenitic stainless steel, Cold rolling, Laser weld, Microstructure, Texture component