During isochronal tempering of martensitic steels, several decomposition reactions take place within to some extent overlapping temperature regions. For the kinetic study of these reactions, differential scanning calorimetry and dilatometry are well established complementary experimental techniques. During tempering stages II and III of martensitic steels with increased carbon contents, the simultaneous transformation of retained austenite and the precipitation of cementite produce strong signals as well in the differential scanning calorimeter as in the dilatometer. For the determination of the individual kinetic parameters and reaction enthalpies, these reactions have to be separated, which is attempted in the present study. This is accomplished by tempering room temperature quenched as well as liquid nitrogen quenched specimens in a differential scanning calorimeter. The investigated material is the SAE 1070, a spring-steel with 10 vol% retained austenite after quenching to room temperature. The data evaluation procedure is explained in detail and the results are compared with literature data. (C) 2011 Elsevier B.V. All rights reserved.