The second stage of tempering

This thesis reports an investigation into the transformation of austenite during the second stage of tempering of a 1.86 % C experimental steel. A survey of relevant literature relating to phases, phase transformation, heat treatment and tempering in steel is presented in Chapters 1 to 4. Experimental work is presented in Chapters 5 to 7 and concerns the surface relief effects generated during the second stage, the characterisation of the carbide in the major product, the comparative effects of pre-existing martensite and bainite on the progress of the second stage and the habit plane of small platelets in the transformation product. The crystallographic properties of the products were studied using a combination of optical and transmission electron microscopy.