Influence of phase composition of austenitic-martensitic trip-steel VNS9-Sh on characteristics of dry sliding friction in tribocontact with steel ShKh 15

The influence of content of the martensite phase that is from 0 to 50% (vol.) on hardness and tribomechanical properties of trip-steel VNS9-Sh (ВНС9-Ш) under conditions of dry sliding friction on steel ShKh15 (ШХ15) (counterbody) has been investigated. It was found out that the best combination of hardness and wear resistance was possessed by steel with martensite phase content ≈32% (vol.). It is shown that with comparable hardness and tribomechanical properties, VNS9-Sh steel is more than twice as strong as 110G13L steel (110Г13Л).

Modernization of friction unit of a KT-2 tribometer for evaluation of the friction properties of thin coatings upon friction in boundary lubrication conditions

The results of studying the tribological characteristics of thin coatings of steel parts on a modernized friction unit of a KT-2 machine in the boundary lubrication mode are presented. To provide high accuracy and reproducibility of the results standard elements of rolling bearings — balls and rollers, which are characterized by the uniformity of the structure and composition, as well as high quality of the surface treatment are used as samples. The developed design of the mandrel ensured friction contact of the ball mounted on the machine spindle with the ends of three rollers mounted with high accuracy at an angle of 35°30’ to spindle axis of the installation to ensure the same distribution of the axial load between three rollers like in the case of the four-ball contact between three lower balls. The coatings under study were applied to the flat ends of the rollers, which is much easier than their application to cylindrical or spherical surfaces. A standard ball made of steel ShKh-15 or wear-resistant ceramics served as a counterbody. The modernized unit is recommended to be used on traditional four-ball machines for laboratory assessment of the effect of thin wear-resistant coatings on the antifriction properties of lubricants.

Problems of Selection of Lubricants for Ethylene High-Pressure Compressors. 4. Investigation of antifriction properties of naphtene and polyglycol oils during high loading of solid lubricant pair

The antifriction properties of naphtene and polyglycol oils during little loading with lubrication of pair bronze-tungsten-carbide-alloy WK-6 (WK-ll) and graphelon-20-WK-6 (WK-11) and high loading with lubrication of pair ball-bearing-high-chromium steel ShKh-15 - steel ShKh-15 are investigated. New correlations of viscous-and-thermal and antifriction properties of different polyglycol oils permit to creating effective composition on its base. The dependence of seizure loading during testing on FBFM on the molecular mass of different polyglycols, wear spot on the axial loading and boundary loading on concentration of additives in naphtene and mineral oils are found. The mean-square relative deviation of diameter of spot of wear from the spot by Hertz give generalization assessment of antiwear properties of lubrication oils.

Improvement of Surface Quality and Parts Functional Ability by Vibro-Mechanical Consolidation Treatment and Finishing

The area of actual contact of surfaces is essential for longevity and successful operation of mobile and immobile interfaces of machine parts. Wear resistance of friction surfaces, reliability adjustments, heat conduction, conductivity and several other functional characteristics of parts are closely related to actual contact area, and thus they influence the working ability of part surfaces. In this regards, the area of actual contact can be considered as one of the parameters of surface quality. This contact area presents a formed surface of plastic deformation, after the contact of the vibro-percussion treated environment or device, and is the essential process of consolidation of vibratory treatment and finishing. The formed plastic deformation surface is also a kind of micro relief surface, characterized by multitude closed and superimposed on each other traces of contact with the particles working environment cultivated surface. This paper presents the results of vibro-mechanical treatment research, its influence on treated surface quality and working ability of the samples contact surface made by hardened steel ShKh-15, the nickel steel 40HNS2MA and bronze alloy BROF7-0,2.