The influence of austenitizing and chemical composition on the microstructures of shape memory stainless steel

Abstract

In this work, three stainless steel alloys (Fe-Mn-Si-Cr-Ni) with shape memory effects were studied by varying austenitizing time and temperature-from 800°C to 1050°C for 2400s and from 600s to 57600s at 1050°C-followed by a water quenching. Optical microscopy results showed no grain size variation up to 900°C with its average dimensions around 30μm. From 950°C to 1050°C, an increase of grain size was noted when compared to 900°C and less. It is possible to note an increase of twice the grain size from 950°C to 1050°C. The results also show that the influence of the treatment temperature on grain growth seems to be more significant than the time elapsed. Also, it was observed that the grain growth depended on the chemical composition, being lower for the alloy with lower manganese and higher chromium content.

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