Abstract
Analytical calculations and experimental measurements of volume fraction of bainitic ferrite and volume of the untransformed austenite indicate that there is a necessity of carbides precipitation. A consequence of the precipitation of cementite during austempering is that the growth of bainitic ferrite can continue to larger extent and that the resulting microstructure is not an ausferrite but it is a mixture of bainitic ferrite, retained austenite and carbides.