Analysis of work hardening mechanisms in Quenching and Partitioning steels combining experiments with a 3D micro-mechanical model

Quenching & Partitioning (Q&P) steels owe their good strength-ductility combinations to the martensite/austenite (α’/γ) mechanical interactions and formation of mechanically-induced martensite (α′mech) through transformation-induced plasticity (TRIP) effect. An essential role is played by carbon, whose distribution among phases can be modified Q&P route. This study presents a methodology systematically quantitatively examine influence α’/γ on overall work hardening steel with respect carbon in martensite. The rests generation 3D micro-mechanical model that allows derive, crystal simulations, response mechanically-stable virtual microstructure. In combination theoretical knowledge hardening, comparison between experimental simulated responses enables quantification content TRIP strengthening contribution steel. approach applied two low Q&P-processed microstructures similar initial volume fractions austenite α′mech kinetics strain, but one containing Nb-microaddition displaying improved values. It shown strength ability might additionally enhance or partially counteract from austenite-to-α′mech transformation during uniaxial loading. results this highlight processing-dependent properties carbon-depleted should considered optimization processed steels.