The influence of the stacking fault energy upon the microstructure, mechanical properties and deformation behaviour of stainless steels before and after irradiation was investigated. The mechanical properties, such as strength, ductility, strain hardening and irradiation induced hardening behaviours of 3 alloys with various stacking fault energies were quite different. Such significant variations of mechanical properties were suggested to result from the differing microstructures, deformation mechanisms and defect-accumulation behaviours. Thus, the microstructures, deformation mechanisms and irradiation-induced small defect clusters (including their types, natures, densities and size distributions) of 3 alloys were determined in detail by transmission electron microscopy. This indicated that, before irradiation, an alloy with a low stacking-fault energy exhibited a more localised deformation behaviour than did an alloy having a high stacking-fault energy. After irradiation, in samples with a low stacking-fault energy, irradiation induced stacking fault tetrahedra were observed while, in ones with a high stacking-fault energy, the predominant defects were Frank loops. All of the results showed that stacking-fault energy had a strong effect upon both the deformation mechanism and the irradiation-induced defect accumulation behaviour in stainless steels.

Deformation and Microstructure of Neutron Irradiated Stainless Steels with Different Stacking Fault Energy. X.Li, A.Almazouzi: Journal of Nuclear Materials, 2009, 385[2], 329-33