A method for testing lubricants under conditions of scuffing. Part I. Presentation of the method

Abstract

A method for the tribological assessment of lubricants under conditions of scufing is presented. The method uses a four-ball tester, and allows one to assess the effect of lubricant on scuffing intensity through an analysis of changes in thefriction torque and wear of the stationary balls, at continuously increasing load. The behaviour of a lubricant under scufing conditions can be characterised using the so-called limiting pressure of seizure poz, which depends on the load at which the balls seize and the average value of the wear area calculatedfrom the wear-scar diameters measured on the stationa y balls.A comparison is made -from the point of view of the resolution, time consumption, and costof the new method with the existing, standard tests, using a four-ball tester and a gear test rig (FZG). It is concluded that the proposed mefhod, unlike standard FZG and certain four-ball tests, enables one to differentiate between gear oils, in agreement with their APl GL performance level. The very short run-time of the new method enables one to perform more tests and obtain a low standard deviation. The new method is much cheaper than the standard four-ball and FZG methods.

Characterization of Tribological Properties of Greases for Industrial Circuit Breakers

“…The EP properties were calculated through the pressure loss limit (poz) on a T-02U four-ball tribotester, following the ITeE-PIB Polish test method for testing lubricants under scuffing conditions [14]. This method measures the influence of lubricants on the propagation of scuffing and the intensity of wear through the wear scar diameter (WSD).…”

“…The tribological properties of wear, load-carrying capacity, and pressure loss limit of greases were determined using a T-02U Four-ball tribotester according to ASTM D 2266 [13] and the ITeE-PIB Polish test method for testing lubricants under scuffing conditions [14]. The coefficient of friction (COF) and wear mass loss were characterized by a T-11 Ball-on-disk test according to ASTM G 99 [15].…”

The New Methods for Scuffing and Pitting Investigation of Coated Materials for Heavy Loaded, Lubricated Elements

“…During the run the friction torque is observed until seizure occurs. The test conditions are as follows: rotational speed: 500 rpm, speed of continuous load increase: 409 N/s, initial applied load: 0 N, maximum load: 7200 ± 100 N. The methods are described in detail in works (Szczerek & Tuszynski, 2002) Scuffing initiation occurs at the time of a sudden increase in the friction torque -point 1. The load at this moment is called the scuffing load and denoted P t .…”

Evaluation of Tribological Properties of Polymer Materials Used for Sliding Bearings in Agricultural Machinery

“…working conditions of contact elements, the ability to create a polymer film (transfer of material) or generated heat (Menezesa et al, 2011). The wear resistance of materials not only depends on the mechanical and structural properties of the materials used but also on the testing technique, as it was reported in (Harsha, 2011;Bahadur and Gong, 1992;Cenna et al, 2003;Dykha and Kuzmenko, 2015;Ptak, 2016;Szczerek and Tuszyński, 2002). In case of lubrication-free polymer bearings, there is no need for maintenance, as in case of bronze or brass sleeves.…”