Role of stress-induced martensitic transformation in TRIP effect of metastable austenitic steels

Abstract

Abstract The effect of the Ni equivalent (Ni eq . ) on the transformation-induced plasticity (TRIP) effect in metastable austenitic steels was investigated to clarify the conditions of stress-induced martensitic transformation behavior for maximum uniform elongation. Results of static tensile tests showed that the tensile strength increased with decreasing Ni eq . and that uniform elongation reached a maximum value at the Ni eq . of 23.7%. The volume fraction of martensite at the same true strain increased as the Ni eq . decreased. The conditions under which the stress-induced transformation resulted in the maximum uniform elongation due to the TRIP effect in the metastable austenitic steels were summarized in terms of the volume fraction of stress-induced martensite and the rate of transformation, which were almost coincident with previous results.