Precipitation of carbides during tempering of high carbon martensite

Abstract

The first stage of tempering which produces a large contraction in length and a decrease of the temperature derivative of resistivity does not correspond to the epsilon- carbide formation but is assumed to be the segregation of carbon atoms to the lattice defects or the formation of carbon clusters. The epsilon- carbide precipitation occurs in the temperature range between 150 and 250 C accompanying a slight decrease in electrical resistivity. The retained austenite decomposes into lower bainite in the temperature range between 230 and 330 C.