Effect of the initial structure state on decomposition of austenite solid solution

Methods of electron microscopy were used to investigate the decomposition mechanisms of a solid austenite solution in a dispersion-hardening Fe-Ni-Cr-Mn-V-C alloy non-deformed and deformed by hydroextrusion. Three types of materials were detected in the annealed alloy at decomposition of the solid solution, namely those situated on matrices, on dislocations and on flaws in vacancy-type packings. Ageing of the extruded alloy was noted to result in carbide materials on dislocations and packing defects this being accompanied by increasing particle dispersion. Ageing processes in a deformed alloy begin at lower temperatures than those in an annealed alloy. Deformation of the alloy by hydroextrusion and subsequent ageing result in considerably increased strength and good plasticity