Microstructural zones in the primary solidification structure of weldment of 9Cr-1Mo steel

The present article describes the microstructural heterogeneity in the weldments of 9Cr-1Mo steel, in the as-welded condition. The thermal cycle, which each microscopic region undergoes, depends on its distance from the source of heat. The consequent differences in the type of phase transformations experienced by the various zones are established using detailed analytical transmission electron microscopy studies. Based on these studies, distinct microstructural zones are identified and the temperature profiles of the same are deduced.