Influence of Cutting Fluids on the Mechanism of Self-Organization and Physical and Mechanical Properties of Wear-Resistant Ultra-Fine-Grained and Nanostructured Surface Friction Layers of Chromium Steels
V. V. Tykhonovych
Институт металлофизики им. Г. В. Курдюмова НАН Украины, бульв. Академика Вернадского, 36, 03142 Киев, Украина
Получена: 12.09.2023; окончательный вариант - 02.10.2023. Скачать: PDF
The cutting-fluids’ influence on the mechanism of self-organization on the friction surfaces of wear-resistant superfine-dispersed coatings is studied. These coatings cause the transition of the friction pair steel 130Х17–steel 20Х13 to a stationary mode of operation with minimal wear and friction coefficient. As shown, the self-organizing wear-resistant coatings consist of friction layers, each of which is the result of a separate act of metal microvolumes layering on the working surfaces due to the adhesive interaction of microroughnesses. The introduction of cutting-fluid concentrates into water changes the chemical composition and energy of the friction surfaces; this leads to layering of larger metal volumes on the working surfaces. As a result, the average thickness of the friction layers increases by 7, 6 and 3 times, when using the ‘Сінтал-2’, ‘Аквол-15П’ and ‘Естераль’ cutting-fluid concentrates. The running-in period of the friction pairs is reduced by 1.8, 1.7 and 1.4 times, respectively. As shown, the introduction of ‘Естераль’ cutting-fluid concentrate into water cannot significantly reduce the adhesive interaction between rubbing bodies. In this case, friction surfaces are shielded only by adsorbed hydrocarbon molecules and thin oxide films. Therefore, the use of cutting-fluid concentrate ‘Естераль’ does not eliminate the predominant mass transfer of steel 130Х17 to the surface of steel 20Х13 during the operation of the friction pair. Self-organizing wear-resistant coatings of both steels are formed mainly from the material of steel 130Х17. Therefore, its weight wear is 1.5 times higher than the weight wear of steel 20Х13 that reduces the service life of the friction unit. The introduction of cutting-fluid concentrates ‘Сінтал-2’ and ‘Аквол-15П’ with extreme pressure and anti-wear additives into water modifies chemically friction surfaces. In this case, layers of chemical compounds of the decomposition products of the additives are additionally formed at the contact areas of the rubbing bodies. This reduces the adhesive interaction of contacting microprotrusions, reduces the amplitude of cyclic loads on self-organized wear-resistant coatings, and prevents metal mass transfer between rubbing bodies. Thanks to this, the cutting fluids ‘Аквол-15П’ and ‘Сінтал-2’ increase the wear resistance of friction pairs by 4 and 5 times, respectively. In addition, the friction coefficient decreases by about 2 times. At the same time, the formation of self-organized wear-resistant coatings occurs mainly from the material of the body, to which they belong, that makes the wear of the components of the friction unit more uniform.
Ключевые слова: sliding friction, wear resistance, cutting fluids, nanostructured material, ultradispersed structure, plastic deformation, surface layers of friction, mass transfer.
URL: https://mfint.imp.kiev.ua/ru/abstract/v46/i02/0151.html
PACS: 06.60.Vz, 62.20.Qp, 68.35.Ct, 68.37.Hk, 81.07.Bc, 81.16.Rf, 81.40.Pq