The structures and properties of the CrC-TiC type duplex layers with an intermediate chromium carbide sublayer and an outer one of titanium carbide, as well as of the TiC-CrC type layers with an intermediate titanium carbide sublayer and an outer one of chromium carbide, produced on steels, were investigated. The structure of the duplex layers produced on plain carbon and alloy steel was compared with the single layers. The microstructure and chemical composition of these layers was determined by means of optical and transmission electron microscopy and X-ray phase analysis. A spectral linear analysis of the Cr, Fe, and Ti concentration in the diffusion zone was performed by means of an X-ray microanalyzer. Proof was presented that the thickness of the outer TiC layer depends on the thickness of the intermediate chromium carbide sublayer. This sublayer slows down the formation of the outer TiC layer. The structure of the chromium carbide sublayer undergoes changes during the process formation of the titanium carbide layer. The hardness and tribological properties of the layers have been determined. A comparison of CrC-TiC and TiC-CrC duplex layers with the CrC and TiC single carbide layers was performed. It was shown that the tribological properties of the CrC-TiC duplex layers are better than those of the TiC-CrC duplex layers, and those of the CrC and TiC type single carbide layers.