Cinética de reversão da martensita para austenita durante o recozimento do aço inoxidável austenítico ASTM 201LN laminado a frio usando o refinamento de Rietveld

This work presents a study of the α’ martensitein austenite () reversion kinetics during annealing at 750 ºC with distinct soaking times (1, 5, 10 and 15 minutes) of the ASTM 201LN austenitic stainless steel, cold rolled at room temperature. Phase quantification analyses were carried out using X-Ray Diffraction (XRD) results and applying the Rietveld refining method in comparison with full-pattern summation method and ferritescopy analysis. Additionally, scanning electron microscopy (SEM) and Vickers hardness (HV) were employed to evaluate the evolution of the microstructure and hardness mechanical property, respectively. The results of the Rietveld method were similar to the ferritescopy quantification values. The full-pattern summation method overestimated the martensite phase percentage. The proposed annealing in its maximum soaking time was able to promote a significant microstructural refinement in a fully austenitic matrix together with a substantial hardening provided by this grain refinement.