Electron-beam modification of a surface layer deposited on low-carbon steel by means of arc spraying

Abstract

State-of-the-art means of physical materials science are used to study the structure, phase composition, defect substructure, and tribological properties of a coating formed on low-carbon Hardox 450 martensite steel via the electrocontact deposition of an Fe–C–Ni–B wire and modified through subsequent irradiation with high-intensity pulsed electron beams. It is shown that electron-beam treatment results in the formation of a modified 50-μm thick surface layer, the main phases of which are the α-phase, iron boride FeB, and boron carbide B₄C. In the layer modified by electron-beam treatment, the transverse size of batch martensite crystals is reduced by a factor of 3, relative to the initial Hardox 450 steel, and ranges from 50 to 70 nm. It is established that the wear resistance of the deposited layer after electron-beam treatment grows by more than 20 times with respect to the wear resistance of Hardox 450 steel, and the friction coefficient is reduced by a factor of 3.5. The microhardness of a deposited layer ~7 mm thick is more than double that of the base metal.