Prediction of the local deformation mechanisms in metastable austenitic steels from the local concentration of the main alloying elements

Abstract

The activation of different deformation mechanisms in high-alloy austenitic steels depends strongly on the concentration of the alloying elements, as they change the driving force for the martensitic phase transformation and the stacking fault energy in the austenite. Consequently, local chemical gradients alter the local deformation behaviour tremendously. In this contribution, the correlations between the local chemical composition, the corresponding difference between the Gibbs energies of austenite and α′-martensite, martensite start temperature, stacking fault energy, observed stacking fault density and the prevailing deformation mechanism are illustrated.