2020 Volume 60 Issue 6 Pages 1349-1357
The better uniform elongation of the 1 GPa-grade TRIP-aided multi-phase steel with retained austenite (γR) shape of needle-like was discussed by in situ neutron diffraction experiments during tensile test. The better uniform elongation can be ascribed by not only the deformation-induced martensitic transformation of γR but also the deformation behavior of γR and ferrite phase. Especially, the tensile deformation behavior of γR is found to be closely associated with both of the stress-strain curve and the deformation-induced martensitic transformation of γR. The tensile deformation behavior of γR should be considered as one of the conditions to obtain better TRIP effect.