Precipitation of Carbides in Early Aging Stages and Their Crystallographic Orientations in Hadfield Steel Mn13

The methods of transmission electron microscopy (TEM) and electron diffraction are used to study the carbides precipitated in Hadfield steel Mn13 during 2-h aging at 475A degrees C. It is shown that carbides of types (Fe, Mn, Cr)(23)C-6 and mixed (Fe, Mn, Cr)(7)C-3 + (Fe, Mn, Cr)(3)C precipitate simultaneously over austenite grain boundaries. The data on precipitation of M23C- and M7C3-type carbides in a Hadfield steel after water quenching and aging are pioneer ones. Strict orientation relations of the M23C6 carbides and of the austenite matrix are determined.