Microstructural characterisation of F82H-mod. steel using small-angle neutron scattering

Small-angle neutron scattering (SANS) measurements have been carried out on samples of F82H-mod. martensitic steel submitted to different treatments: (a) hardening, (b) tempering and (c) ageing. Size distribution functions referable to the precipitates, formed during the different treatments are obtained both for nuclear and magnetic SANS components. The results, discussed making reference to transmission electron microscopy (TEM) observations and microhardness measurements, show that while samples of groups (a) and (c) exhibit a stable microstructure, marked differences are detected varying the tempering temperature, especially at 550 degrees C (where a fine precipitation is observed) and for temperatures higher than 850 degrees C (formation of delta ferrite). (C) 1998 Elsevier Science B.V. All rights reserved.