Reverse martensitic transformation and resulting microstructure in a cold rolled metastable austenitic stainless steel
2008 (English)In: Steel Research International, ISSN 1611-3683, Vol. 79, no 6, 433-439 p.Article in journal (Refereed) Published
The reverse martensitic transformation in cold-rolled metastable austenitic stainless steel has been investigated via heat treatments performed for various temperatures and times. The microstructural evolution was evaluated by differential scanning calorimetry, X-ray diffraction and microscopy. Upon heat treatment, both diffusionless and diffusion-controlled mechanisms determine the final microstructure. The diffusion reversion from α′-martensite to austenite was found to be activated at about 450°C and the shear reversion is activated at higher temperatures with Af′ ∼600°C. The resulting microstructure for isothermal heat treatment at 650°C was austenitic, which inherits the α′-martensite lath morphology and is highly faulted. For isothermal heat treatments at temperatures above 700°C the faulted austenite was able to recrystallize and new austenite grains with a low defect density were formed. In addition, carbo-nitride precipitation was observed for samples heat treated at these temperatures, which leads to an increasing Ms-temperature and new α′-martensite formation upon cooling.
Place, publisher, year, edition, pages
2008. Vol. 79, no 6, 433-439 p.
IdentifiersURN: urn:nbn:se:liu:diva-44668DOI: 10.2374/SRI08SP039-79-2008-433Local ID: 77260OAI: oai:DiVA.org:liu-44668DiVA: diva2:265530