Ultra-high tensile strength via precipitates and enhanced martensite transformation in a FeNiAlC alloy

Aging and quenching at critical temperatures were applied to a hot-rolled (HR) Fe-24.86Ni-5.8Al-0.38C (mass%) dual-phase alloy obtain B2 precipitates with various volume fractions sizes. Higher yield strength stronger strain hardening achieved in the aged samples compared these for HR sample, corresponding deformation mechanisms carefully revealed. The show hetero-deformation induced that sample. amount of phase transformation during tensile tests is much higher sample due reduced stability austenite phase, which can be attributed high local stress level by undeformable hard around grains reduction nickel aluminum diffusion from aging. Deformation-induced lath martensite dislocation density observed after deformation, transformation-induced dislocations should have great impact on hardening. Moreover, twins becomes deformation-induced nanotwins contribute significantly hardening, as dynamic Hall-Petch effect.