Effect of copper on strain-induced martensite and the parameters that simulate the stress-strain curve of an austenitic stainless steel AISI 304

Purpose: This study examined the effect of copper on the phase transformation (γ → a')-induced by the deformation and in the variables of the equation that simulates the stress- equivalent strain curve. Design/methodology/approach: The phase transformation (y → a') was studied through the magnetic properties using a vibrating sample magnetometer - VSM. The simulation of the stress-equivalent strain curve was performed using the obtained results in experimental studies, using the commercial software Maple. Findings: It was observed that the addition of copper in the austenitic stainless steel (ASS) AISI 304 promotes increased stability of the austenite, slowing therefore, the formation of martensite induced by deformation. It was also observed that the addition of copper influences on the values of the variables of the equation that simulate the stress-equivalent strain curve. Research limitations/implications: The stress-equivalent strain curve was simulated satisfactorily, however it was observed that the equation that simulates the curve displays values of the variables not usually found, this may be due to the approximations made in applying the rule of mixtures. Practical implications: It was observed that with the increase of copper, the ASS tend to increase the stability of the austenitic phase, which implies a delay in hardening of the material and a probable influence on the variables of the equation that simulates the stressequivalent strain curve. Originality/value: The influence of copper on the formation of magnetic martensite (a') and consequent influence in obtaining the variables of the equation that generates the stress-equivalent strain curve.