In situ X-ray diffraction study of martensitic transformation in austenitic stainless steel during cyclic tensile loading and unloading

In situ X-ray diffraction was carried out to identify and evaluate strain-induced martensitic transformation in 304 austenitic stainless steel under cyclic tensile loading and unloading. Experimental results indicated that the fraction of strain-induced martensite increases due to the alteration of the internal structure involving the internal stress and dislocation configuration when unloading occurs. It is found that the enhanced transformation-induced plasticity effect can prolong the time to neck formation to a significant extent.