The morphology of TiC carbides produced in surface layers of carbon steel castings

The study presents the results of investigations of the process of in situ fabrication of TiC carbides in a surface layer of carbon steel casting. Carbides were produced by SHS reaction taking place between the substrates deposited on mould surface and cast molten alloy. The thickness of the obtained layer was up to 700 μm, and the size of carbides was comprised in a range of 1-10μm. During alloy solidification in mould, a thermal analysis was carried out; its results were used in evaluation of the morphology of the obtained titanium carbides. It has been found that, at the moment of reaction, the temperature of the reaction layer and the temperature of the central part of casting differed by 93 K. This difference has changed the morphology of the obtained carbides. In the region of reaction layer, where the temperature amounted to 1955 K, the crystals assumed an oval and coagulated shape, while at the layer-casting interface, TiC carbides in the form of cuboids were formed.