Russian Metallurgy (Metally)最新文献

The works performed in FGUP VIAM to develop high-temperature cobalt- and nickel-based materials for the SLM technology are reviewed. They are compared with foreign analogs in terms of application and with the materials produced by traditional technologies. Promising works in the field of synthesizing high-temperature and intermetallic materials with a given texture are described.

Abstract—The direct oxidation of a metal with hydrogen peroxide in the metal–iodine–hydrogen peroxide–acid–organic solvent system, which is competitive with the reaction with iodine, is found to cause the anomalously high rates of lead consumption. The kinetics of this reaction in the absence and presence of other metals is studied. Under these conditions, other metals are shown to be consumed much more slowly, which is not competitive, on the one hand, with their reactions with iodine; on the other hand, their products appreciably retard the direct interaction of lead with hydrogen peroxide.

A silicon-containing material based on non-market (unsized) fractions of the magnesium-containing modifiers for the production of high-strength cast iron and vermicular graphite cast iron (VGCI) is proposed for ironmaking as an alternative of the popular FeSi45 ferroalloy. The economical scheme of a reasonable alternative application and specific features of the chemical composition and interaction of the silicon-containing material with molten cast iron are presented. The efficiency of its use for ironmaking in electric-arc furnaces has been confirmed in practice.

The laser treatment of a Ni–W galvanic coating is modeled. The temperature distribution across the coating thickness is calculated. Experimental studies for the verification of the model are carried out. A three-dimensional finite-element method implemented in the Comsol Multiphysics 5.4 software is used for the simulation of thermal effects. The laser treatment model showing a good convergence with the experimental data has been developed.

The trends in the development of a technology for the production of the hot gas path parts of a gas turbine engine (GTE) by directional solidification from superalloys are considered. The existing special-purpose equipment used in Russia, the United States, Germany and other countries to produce blades with a directional and single-crystal structure is analyzed. The prospects of directional solidification with a liquid metal cooler in the production of GTE blades for both modern and promising GTEs are clearly demonstrated.

Abstract—Relations are proposed for calculating combined conditions for drawing with heating during metal forming. The workpiece material is taken to be anisotropic and viscoplastic. The extremum upper-boundary plasticity theorem and the damage kinetics equations of a deformed material are used. Calculated data are obtained.

Abstract—The implantation of aluminum ions into the surface layer of a VT6 titanium alloy and the deposition of an aluminum thin film on the alloy surface by magnetron sputtering with subsequent ion-beam mixing by argon ions are studied. The evolution of the composition of the ion-alloyed layer in the VT6 titanium alloy after aluminum-ion implantation is demonstrated.

Abstract—An algorithm for estimating the yield strength increment as a result of solid-solution and precipitation hardening of the surface-alloyed layers in iron, which are formed during combined saturation with a nitride-forming metal (Cr, V, Ti, W, Mo) and nitrogen. The input parameter for the estimating calculations is the alloying metal concentration in iron, which is quantitatively related to the structural factors of hardening, namely, the concentration of dissolved nitrogen and the volume fraction of precipitated nitrides. A high degree of correlation is found between the calculated hardening parameters and the microhardness of the modified layers in armco iron after diffusion metallization (by chromium, titanium, and vanadium) and nitriding.

Currently, additive technologies, in particular, electric arc growth as the most universal and productive, are used to produce individual machine parts. The problem of studying the process of structure formation in alloys during electric arc additive growth to ensure the necessary parameters of the microstructure of a material and its mechanical properties is challenging. 09G2S steel samples for research are fabricated on a developed test bench implementing the technology of 3D printing by electric arc surfacing, microstructural studies on an optical microscope are used, and microhardness measurements are carried out. The features of structure formation in a 09G2S alloy during additive electric arc growth have been determined, and controlled parameters have been identified to ensure the necessary parameters of the structure and, consequently, the mechanical properties of the alloy. The heat input of the surfacing process and the temperature of a thermal cycle are found to play a significant role in the structure formation in the material. The conducted research and established dependences make it possible to control the structural state of 09G2S steel during cladding to ensure the required parameters of its microstructure and mechanical properties.