METHOD OF INSERTING CARBIDES AND OXIDES OF REFRACTORY METALS INTO SURFACE LAYER OF CARBON STRUCTURAL STEELS BY COMBINED PLASTIC DEFORMATION

摘要

FIELD: machine building.;SUBSTANCE: invention relates to methods of implanting materials based on tungsten carbide in the surface of machine parts and can be used in machine building, aviation, automotive and other industries. Method involves treatment of steel surfaces of parts in open atmosphere by application on friction surface of steel parts of coating, consisting of powder of tungsten carbide with particle size of up to 9 mcm, mixed with consistent graphite lubricant, and performing combined electromechanical treatment in two stages. At the first stage, tungsten carbide powder is introduced in the mode of "high-temperature plastic deformation" from graphite coating by rolling 95X18 steel roller on the part surface under a certain load. At the second stage, in the "high-temperature thermal hardening" mode, a roller is used from pseudoalloy "tungsten-copper carbide" to provide combination of high temperatures and pressures in the contact zone, under action of which at moment of electric pulse austenization of steel surface layer occurs in contact zone of roller and processed surface. At that, three-layer gradient structure is formed, consisting of first upper, hardened layer with thickness of 180–220 mcm, saturated with initial particles of tungsten carbide, second lower layer with thickness of 200–250 mcm, consisting of cellular structure of austenite grains, the boundaries of which are reinforced with carbide-tungsten mesh, and third layer with thickness of 20–40 mcm, saturated with tungsten carbides.;EFFECT: invention enables to form a qualitative surface layer by increasing depth and degree of hardening of the surface with achieving its stable phase, micro- and nanostructured state, which ensures optimum tribotechnical indices of working surfaces of parts of machines and mechanisms.;1 cl, 8 dwg, 6 tbl