We investigated 18CrNi3MoA-SH steel, hardened by electrolyte-plasma processing method. Scanning analysis of transient surface demonstrated that in the course of details’ electrolyte-plasma heating chemical surface modification takes place along with tempering. Unit value of micro hardness on the crosscut is estimated. Micro hardness twofold increase concerning initial condition testifies to material hardness after electrolyte-plasma processing. This method advantages are minor energy expenditure in the time of tempering high speeds, possibility of local surface processing especially of large size details with complicated shape. 18CrNi3MoA-SH steel hardening by electrolyte-plasma method is performed on semi-industrial installation constructed at D.Serikbayev EKSTU in collaboration with «TehnoAnalyt» Ltd., Ust-Kamenogorsk. The detail heating temperature is 930 - 9400С, overall time of processing is approximately 5 minutes, hardening is produced at 860 - 8700C then cooled in electrolyte flux. Electrolyte composition is 10 %-s' Na2CO3 and C3H8O3. The metallographic analysis was realized on «NEOPHOT 21» microscope. The qualitative and quantitative phase analysis of steel structure was carried out on PANanalytical" X-Ray diffractometer involving Cu-K radiation. Microhardness determination was measured on PMT-3 device with diamond cutting point; by indentation load 1 N according to State Standard 9450-76.

Microhardness of nitrated and carbonitriding in electrolyte plasma steel Р6М5 surface layers are investigated in the research. It shows perspectiveness of the cutting tool electrolyte-plasma treatment technology. Operating conditions for the technology realization are defined. It was also indicated the desired content of components in saturating mixtures by nitriding and carbonitriding. Comparative research of structure, phase composition of fast-cutting P6M5 steel modified surface layers after electrolyte plasma treatment was carried out by scanning-electron and light microscopy, and X-ray structure analysis methods. The way of electrolytic plasma nitriding in cathodic mode, to provide fast-cutting steels which allows for modification the surface and high kinetic efficiency the process diffusion saturation. It was established that as a result of nitriding and nitrocarburizing in plasma electrolyte has been a significant increase in microhardness in the surface layers of steel Р6M5.

Investigated the fragmented substructure of steel 30CrMnSiA after heat treatment and deformation. Found that after heat treatment of steel is the main component of α-phase (~ 96%), γ- phase (~ 3%) is present in the material in the form of residual austenite. Batch martensite is 0.7 on the volume of α- phase plate - 0.3. Most of the residual martensite (1.5%) is located in the plate martensite, the lowest - in a fragmented packet martensite component (~ 0.5%). In unfragmented batch martensite of residual austenite is present in an amount of 1%. Found that in the process of deformation martensite structure formed after heat treatment is completely destroyed and the volume fraction of anisotropic fragments is 25%, 75%-isotropic. Electron microscopic studies have shown that originated fragmented structure is stabilized by tertiary carbides formed during deformation. These carbides are cementite particles and special carbide M6C. These particles are located mainly along the boundaries and junctions of the fragments.

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The research shows the results of electrolyte-plasma treatment influence on structure-phase state, mechanical properties and wear-resistance of drilling tool steel samples. The comparative analysis of microstructure, microhardness and wear-resistance of the samples in initial state and after electrolyte-plasma treatment is represented. It was found out that 18CrNi3MoA-Sh steel microstructure has fine-grained martensite-bainite structure after the treatment. It was determined that 18CrNi3MoA-Sh steel possesses high wear-resistance after electrolyte-plasma treatment, so that technology is characterized by low power consumption and cost price. The initial state microhardness is 2800 MPa on the average. Microhardness on the bearing lane surface after electrolyte-plasma processing is 7500 MPa on the average. Microhardness increases in 2-2.5 times more before treatment that indicates the technology efficiency.