Nanostructural States and Properties of the Surfacing Formed on Steel by a Cored Wire

Structural-phase states and mechanical properties of electric arc surfacing by an EnDOtec DO*33 cored wire on a Hardox 400 steel are investigated. Formation of the multiphase state of the surfacing represented by grains of α-iron and inclusions of carbide phases based on iron, chromium, and niobium is revealed by the methods of electron diffraction microscopy and x-ray phase analysis. The additional treatment of the surfacing by a high-intensity electron beam is performed. Mutual arrangement of the grains of α-iron and particles of carbide phases is investigated. It is found that the surfacing layer is in the elastic-stressed state formed as a result of super-high heating and cooling rates initiated by the pulsed electron beam treatment. It is shown that the microhardness of the surfaced layer remains constant with the depth down to 4 mm and exceeds by a factor of 2.4 the microhardness of the substrate; the wear resistance of the surfacing is 3 times higher than that of the steel, and the friction coefficient of the surfacing is half that of the steel.