Heat resistance of nitrided layers on high-speed powder steelsMukhin, G.; Pavlov, M.
doi: 10.1007/BF02468244pmid: N/A
Nitriding of cutting tools is used to improve their endurance. The small thickness of the nitrided layers does not make it possible to evaluate their heat resistance by the standard method. This has made it necessary to develop a method for independent determination of the heat resistance of nitrided layers on high-speed steels. This makes it possible to optimize the nitriding process, in particular, for improving the heat resistance of the layers. The present work is devoted to assessing the possibility of increasing the heat resistance of high-speed powder steels R6M5K5-MP and R9M4K8-MP by ion nitriding and to developing a method for evaluating the heat resistance of the nitrided layers.
Structure and properties of amorphous and nanocrystalline chromium-carbon coatingsPuchkov, Yu.; Anan'ev, V.; Larkin, V.; Berezina, S.
doi: 10.1007/BF02468245pmid: N/A
Amorphous and nanocrystalline chronium-carbon coatings have higher properties than standard galvanic chromium ones. However, data on these coatings, and their heat-treatment regimes are quite scarce. The present paper concerns the structure, microhardness, ductility, adhesion strength, and resistance to overall and pitting corrosion of amorphous chromium-carbon coatings deposited galvanically by various regimes in an electrolyte based on chromic anhydride with an additive of formic acid.
Effect of laser treatment on the wear resistance of steelsSafonov, A.; Aleksenko, S.
doi: 10.1007/BF02468246pmid: N/A
It is known that laser hardening increases the wear resistance of friction parts quite substantially. At the same time, many problems connected with the effect of the treatment process and the special features of laser hardening on the characteristics of wear resistance require detailed consideration. The present paper is devoted to the development of recommendations on choosing the optimum location and proportion of the areas of the hardened and unhardened regions of the surface of structural steels after their treatment with radiation of a continuous CO2 laser.
Criteria for evaluating the cooling capacity of quenching mediaKsenofontov, A.; Shevchenko, S.
doi: 10.1007/BF02468249pmid: N/A
Numerous criteria have been suggested for evaluating the cooling capacity of quenching media. Although the cooling capacity of a medium can hardly be evaluated by a single number, such data can be helpful in the initial stage of choosing the medium for quenching a specific part. Various criteria for evaluating the cooling capacity of polymer quenching media have been analyzed within the developed international standard based on ISO 9950 (for industrial quenchants). Those that can be calculated from results of tests of a medium by means of a Wolfson gauge, recommended by the ISO 9950 standard, have been chosen. The aim of the present work consists in determining the correlation between the criteria suggested by various researchers for various domestic and foreign quenching liquids on a polymer base.
Diffusion saturation of nickel alloys with aluminum and chromium from the gas phase by the circulation methodLesnikov, V.; Kuznetsov, V.; Goroshenko, Yu.; Repina, O.; Rozhko, A.
doi: 10.1007/BF02468250pmid: N/A
Protective coatings on parts made of high-temperature nickel alloys increase substantially their service life and resistance to oxidation and corrosion in a high-temperature gas medium. A promising direction in this respect is the use of a gas circulation method for depositing protective coatings that envisages separated positioning of the saturated alloy and the saturating powder containing chromium, aluminum, cobalt, and other elements. Transfer of these elements to the surface of the saturated alloy occurs by means of forced circulation of the gas phase in the closed volume of the installation at a specified temperature. The present work is devoted to the problem of diffusion saturation of the surface of nickel alloys of the ZhS type with Cr and Al by the gas circulation method.
Structure and properties of diffusion layers formed in vacuum cyanidation of steel 20Kh13 in an atmosphere of pyrolysis of liquid hydrocarbonsTarasov, A.
doi: 10.1007/BF02468251pmid: N/A
The use of carburized high-chromium steels with 13–18% Cr for the production of wear-resistant shaping tools and attachments is advantageous for many branches of industry. At the same time, the deposition of carbide diffusion layers on corrosion-resistant high-chromium steels has some special features and technological difficulties, specifically, in quenching, tempering, and polishing of parts and tools. The results described in the present paper and the developed technology of vacuum chemical heat treatment (VCHT), namely, cyanidation of steel 20Kh13 in an active carburizer based on ethanolamines, are of interest for the production of small-size tools and attachments in tool shops of enterprises producing instruments, electronics, watches and clocks, etc.
Short-duration gas nitriding of parts made of high-strength cast iron in the gaz joint-stock companyStarostin, V.; Pytyaeva, E.; Pershina, V.
doi: 10.1007/BF02468252pmid: N/A
Castings of high-strength iron are use very widely. The range of automobile parts cast from iron with globular graphite is widening. It includes crankshafts and camshafts, flywheels, crankcases, various engine parts, etc. In order to increase hardness of the surface layer, the wear resistance, and the service life of parts made of high-strength cast iron, they are often subjected to nitriding. The present work is aimed at studying the nitriding process for parts made of VCh70 and VCh85 high-strength cast iron.