Suppressed martensitic transformation under biaxial loading in low stacking fault energy metastable austenitic steels

Abstract

The effect of uniaxial/biaxial loading on the martensitic transformation of a low stacking fault energy, metastable austenitic stainless steel was studied by in-situ neutron diffraction on cruciform-shaped/dogbone samples. Uniaxial loading favors the martensitic transformation following the sequence γ → ε → α′, where at low strains ε-martensite is the precursor of α′. During equibiaxial-loading, the evolving texture suppresses the formation of ε-martensite and considerably less α′-martensite is observed at high strains. The results are discussed with respect to the deformation textures, the loading direction and the mechanism of the ε-martensite transformation.