Microstructure and Properties of Modified Layer on the 65Mn Steel Surface by Pulse Detonation-Plasma Technology.

The modified layers were prepared on the 65Mn steel surface by pulse detonation-plasma technology (PDT) treatment. The effects of PDT on the morphology, phase structure, microhardness, and crystallographic orientation of 65Mn steel were studied. The modified layer with uniform thickness, compact structure and high hardness can be formed on the surface of 65Mn steel after PDT treatment. It was found that the grains are refined in modified layer, the residual austenite is formed with different physical processes, and the element of electrode is implanted into the surface to cause microalloying effects. Moreover, the microhardness and the wear resistance of the modified layer improve with increasing of treatment pulse. The maximum microhardness of modified layer is up to 794.9HV, and the wear resistance can be improved to be 2.1 times that of the substrate, which might due to grain refinement, dislocation increase and impact hardening. The possible mechanisms of the changes of microstructure and properties in modified layer after PDT treatment were discussed in this paper. [ABSTRACT FROM AUTHOR]