Rezumat
CZU 621.793.164
Tribological aspects of the research of perspective pyrolytic chromium-carbide coatings to increase wear resistance of surfaces of heavy loaded units of vehicles are presented in the article. The values of friction coefficients of the standard ceramic-metal frictional MK-5 materials such as 65Г steel and 40X steel with chromium-carbide coating are received in the speed range from 2 to 6 m/s. A study was carried out in the environment of the oil which applies in hydraulic transmissions of tractors. A comparison of the results of the friction measurements and wear of steel disks with a coating and without it shows advantages of usage of the chromium-carbide coatings: coated 40X steel with the surface roughness Ra ~ 1.8–2.0 microns has a reduced wear up to two orders of magnitude in comparison with a disk of 65Г steel without a coating. Tests of full-size disks in a hydro-mechanical transmission at the real modes of slipping have shown that application of disks with pyrolytic chromium-carbide coatings can increase the service life not less than twice.
Keywords: pyrolytic coatings, chrome carbide, friction, wear, frictional couples.