The changes in the nearest - neighbour surroundings of carbon atoms in the
cementite Fe3C lattice due to the heat treatment are analysed by the Extend
ed Energy Loss Fine Structure (EELFS) method. To study the local atomic str
ucture of the carbon steel U15 after different heat treatment regimes the e
lectron energy loss spectra above the C K edge and Fe L-2,L-3 edge were mea
sured. The measured experimental EELFS spectra were treated by the standard
for the Extended X - ray Absorption Fine Structure method procedure using
Fourier transformation to obtain the parameters of the nearest - neighbour
atomic surroundings. Qualitatively the assumption was made that the number
of the iron atoms in the carbon atom nearest - neighbour surroundings chang
es due to the heat treatment, the evidence of which was the change in the r
atio of the first two feature intensities of the atomic radial distribution
function. This assumption is consistent well with the previous Mossbauer d
ata.