Effect of starting microstructure and intercritical annealing parameters on the microstructure and mechanical properties of a medium-mn third-generation advanced high-strength steel

Third generation advanced high strength steels (3G AHSS) have a superior combination of high strength and ductility that make them promising candidate materials for vehicle light-weighting. The present work investigates the mechanical properties and microstructural development of a prototype 0.15C-6Mn-2Al-1Si TRIP-assisted 3G AHSS arising from heat treatments compatible with the continuous galvanizing process. This study assesses the effects of starting microstructure, intercritical annealing time and temperature and isothermal bainitic transformation parameters on retained austenite volume fractions and tensile properties of the prototype alloy with reference to published U.S. DOE 3G AHSS property targets.