Influence of partitioning parameters on the mechanical stability of austenite in a Q&P steel: A comparative in-situ study

The transformation-induced plasticity (TRIP)-effect is an efficient way to increase the formability in high performance steels. Hence, optimal stability of retained austenite crucial benefit most from this effect. In present work, in-situ energy X-ray diffraction was used study martensite transformation upon uniaxial tensile loading a TRIP-assisted steel produced by quenching and partitioning (Q&P) process. A detailed analysis patterns recorded during deformation allowed with respect applied conditions. found strongly depend on heat treatment, could be mainly attributed carbon content tempering degree surrounding martensitic matrix. Partitioning at 260 °C resulted poor stability, while almost too stable after 360 °C. combination strength ductility for 400 micromechanical behavior analyzed evolution individual lattice strains change full width half maximum (FWHM). Yielding clearly identified FWHM. Martensite showed unexpected peak narrowing yielding. case 2-step Q&P, started yield martensite, yielding occurred simultaneously 1-step Q&P.