Modification of Structure and Properties of Surfacing of High-Speed Steel by Electron-Beam Treatment

The structure and microhardness of a multilayer surfaced on an R2M9 high-speed steel in a nitrogen atmosphere and subjected to high tempering and electron-beam treatment are studied. The surfaced layer structure consists of a tempered martensite, with the carbides and carbonitrides located along the grain boundaries. It is shown that high tempering increases the steel microhardness and gives rise to a transformation of the retained austenite into martensite. An electron-beam treatment forms a honeycomb structure in the surface layer, which provides a factor of 1.1–1.6 increase in the surface layer microhardness over the initial state and that after tempering.