When steel parts are working under heavy-duty conditions, there is always a possibility of the formation of carbides on their rubbing surfaces as a result of decomposition of lubricants and subsequent reaction of carbon with the metal. This process is inevitably associated with local seizing and mutual material transfer. As a result, the carbide phase formed during friction betwen two steels of a different composition may differ from the adjacent material in respect to its content of carbide-forming elements. When strong carbide-forming elements are present in a steel with a friction-induced surface carbide layer, heating such a steel to relatively low temperatures leads to localized decarburization which, under certain circumstances, may reduce the wear resistance of steel. In a simple case of a binary alloy, the rate of decarburization depends on the affinity of the alloying element to carbon.