抄録
In this paper the authors have tried to make clear the tempering process of 0.4% C-steel after quenching by means of electron micrography. The authors also used X-ray diffraction methods and thermal analysis as an aid to interprete the electron micrography. The results, make clear the details of the transformation of ε-iron carbide to cementite, the existence of the platelet cementite at a former stage of the precipitation of cementite and the relationship between the shape of granular cementites and the sub-boundaries on the grain-growth of the granular cementites.