X-Ray Stress Analysis as Related to Tempering and Tempering Kinetics *

With X-ray stress and fine structure analyses, results have been obtained that are inconsistent with present views of the structure and tempering kinetics of hardened steels. Experimental results are reported, and an attempt is made to establish a model of the tempering kinetics of hardened steels. It is shown that the Snoek and Cottrell effects are the dominating mechanisms of diffusion and that they lead to the formation of two α phases of differing carbon content; the phase with the accumulated carbon finally results in the formation of cementite.