The analysis of scientific literature has shown the diffusion saturation of two and more chemical elements of the surface of alloys remains understudied due to the complexity of sample preparation and subsequent analysis of samples. This remains a relevant objective of modern science. Using of a new technique for determining the concentration of a chemical element during chemical-thermal treatment of alloys will greatly facilitate the theoretical studying of diffusion processes in alloys and the practical application of diffusion saturation. The article describes a new method of determining the concentration of chromium during diffusion chromium plating of steel. The possibilities of the new technique are shown on the example of diffusion saturation with chromium of X35CRNI2-3. The principle of the technique – the obtained samples after chromium plating of steel are cut across the axis, thin sections are made, the diffusion layer is examined from the end of the sample using an electron microscope. In this work the analysis technique is based on the capabilities of scanning electron microscopy, X-ray spectral microanalysis of diffusion layers across a section (local determination of the chemical composition of the material). The chemical composition of the diffusion layer was monitored using a universal scanning electron microscope JEOL JSM-6460 LV. Chromium diffusion saturation of steel X35CRNI2-3 has done. A dense (pore-free) surface layer containing 100 to 2% chromium, to 62 microns thick, has obtained. The diffusion coefficient of chromium has calculated: α-phase – DCr = 6.3·10–14 m2/s, γ-phase – DCr = 3.7·10–15 m2/s. The microhardness of the chromiumplated layer has determined, which averaged 1369 HV300.

Known methods of chemical-thermal treatment of structural parts, such as carburizing, nitriding, diffusion metallization technologies, make it possible to obtain a unique combination of surface and core properties of the product. The positive experience of using methods of multi-element diffusion saturation opens up prospects for the development of methods for complex saturation. The article describes the technology of thermal diffusion saturation of steel X35CrNi2-3 with chromium and molybdenum at a temperature of 1000 °C. A technique for analyzing the obtained coating is presented, based on the possibilities of X-ray spectral microanalysis (XMS) of the diffusion layer on transverse microsections of the obtained samples. The elemental composition of the diffusion layer was monitored using a JEOL JSM-6460 LV universal scanning (scanning) electron microscope. The microstructure was studied on an optical metallographic microscope Axio Observer D1.m. X-ray phase analysis was carried out on a Rigaku Ultima IV diffractometer. The hardness measurement was carried out on an FM-800 microhardness tester at a load of 100 g. Data were obtained on the qualitative and quantitative distribution of chromium and molybdenum in the surface layer of steel. It is shown that the resulting thermal diffusion coating consists mainly of a substitutional solid solution based on Cr–Fe–Mo with a bcc lattice and chromium and molybdenum carbides. The depth of the outer coating on the sample was about 20 μm, the depth of the diffusion layer in the base metal was about 25 μm. The absence of a decarburized area in the surface layer of the base metal was noted. The average diffusion coefficients of chromium and molybdenum in the α-phase of chromium were determined DCr = 6.6·10–15 m2/s and DMo = 4.35·10–16 m2/s respectively; in the γ-phase of iron DCr = 2.95·10–15 m2/s, DMo = 2.48·10–16 m2/s respectively. The microhardness of the outer surface layer was 1400–1980 H, the diffusion layer in the base metal was 1000–600 HV, and the base metal was about 540–510 HV.

Termodiffusion saturation of the surface of alloys with two or more elements remains poorly understood despite the great practical and scientific interest that this method of chemical-thermal treatment represents. The simultaneous introduction of several elements can significantly reduce the processing time of products and obtain a multiphase composition on the surface of the product, which opens up wide opportunities for imparting unique technological and operational properties to products. The article describes the features of the distribution of chromium and vanadium during joint thermal diffusion saturation of steel X35CrNi2-3 at a temperature of 1000 °C. The proposed analysis technique is based on the possibilities of X-ray spectral microanalysis of diffusion layers on transverse microsections of the obtained samples. The elemental composition of the diffusion layer was monitored using a JEOL JSM-6460 LV universal scanning electron microscope. The microstructure was studied on an optical metallographic microscope Axio Observer D1.m. X-ray phase analysis was carried out on a Rigaku Ultima IV diffractometer. The hardness measurement was carried out on an FM-800 microhardness tester at a load of 100 g. Data were obtained on the qualitative and quantitative distribution of chromium and vanadium in the surface layer of steel. It is shown that the emerging diffusion coating has the following structure: a structureless outer layer, consisting mainly of chromium, vanadium carbides → a region of columnar crystals (experiencing γ→α transformation upon cooling), consisting mainly of their Cr1.0V0.4Fe0.3 solid solution → partially decarburized α-phase → base metal. The diffusion coefficients of chromium and vanadium are determined: in the α-phase DCr = 1.3·10–15 m2/s; DV = 1.8·10–14 m2/s; in the γ-phase DCr = 1.13·10–15 m2/s; DV = 1.3·10–15 m2/s. The microhardness of the outer surface layer was 1400–1980 H, the diffusion layer in the base metal was 630–790 HV, and the base metal was about 540–510 HV.