Plastic flow behavior and its relationship to tensile mechanical properties of high nitrogen nickel-free austenitic stainless steel

Plastic flow behavior of high nitrogen nickel-free austenitic stainless steel with solution, hot rolling and cold rolling treatments were examined and analyzed by using the Ludwigson equation. It was shown that this stainless steel exhibit a two-stage strain hardening behavior, which can be well described by the Ludwigson equation. Based on the Ludwigson equation and the Considère instability criterion, two equations of the uniform plastic strain and the stress ratio (true ultimate tensile strength/true yield strength) to the strain hardening exponents were derived. Based on these two equations, the dependence of the strength and ductility on the true yield strength and strain hardening behavior was discussed and connected with the observation results of microstructures.