Wear of unlubricated steel surfaces in sliding contact

Wear of unlubricated steel surfaces in sliding contact

SYSTEMATIC ABSTRACTS OF CURRENT LITERATURE ful in understanding failures on disks, and it can be extended to scuff propagation on gears. ASME Seal Sym...

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SYSTEMATIC ABSTRACTS OF CURRENT LITERATURE ful in understanding failures on disks, and it can be extended to scuff propagation on gears. ASME Seal Symposium. JOLT, (Trans. ASME, 90, Ser. F (z)), (April 1968) 333-523; 22 papers corresponding with preprints ASME-67-WA/Lub. 1-22. From the preface by D. F. Hays: The purpose of this recent symposium was to bring together persons with a common interest-seals. In retrospect, I believe that the symposium was successful in achieving its purpose. For three days, the manufacturers and users of seals from both the United States and Europe were present to discuss their latest developments in dynamic seals. The subjects discussed included radial lip seals, face seals, labyrinth seals, and several special purpose seals. Related topics included quality control, elastomer considerations, and fluid behavior.

Problems of Sealing and Wear in Dry-running Piston Compressors. (in German) R. Schubert, Chem. Ing. Tech., 40 (5) (1968) 235-241 ; II figs., 4 refS. The wear of polytetrafluoroethylene piston rings was investigated on a special test rig under conditions that approached those encountered in compressor operation as closely as possible. The results obtained were used to calculate wear factors, which are dependent upon the filling material (glass fibre, carbon, bronze, graphite, and metal oxide), the cylinder material, the surface pressure, the temperature, the gas atmosphere, and the dampness.

5. MATERIALS

AND WEAR

An Experimental Investigation Simulating Machining-type Failures in Turbines. S. 4. Karpe, Lubrication Eng., zq (5) (1968) 216-229; 21 figs., 5 tables, 22 refs. An unusual, severe type of bearing failure which is typified by machining of the harder steel rotor (journal and/or thrust collar surface) has been encountered in marine and land-based turbines. From the appearance of damage, these failures have been called machining of wire-wool failures. The potential magnitude and known consequences of this type of failure on large machinery units has led to the undertaking of an extensive research program, The objective of the program is to determine the causes, mechanisms, and means of eliminating or reducing the risks of such failure. This paper discusses the results obtained from a bench-scale apparatus, run under a range of defined conditions. Under certain conditions, service-type failure can be reproduced consistently. Main emphasis in this paper is

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placed on the effect of the oil environment on susceptibility to, and mechanism of, failure. Also treated is the influence of the rotor metal on failure. It was concluded that there is no single mechanism of failure. Numerous factors and interrelationships are involved. The complexity is compounded by the simultaneous presence of two distinct processes, abrasion and adhesion. An Evaluation of Various Journal Materials with Regard to Machining-typewear.

H. N. Kaufman, Lubrication Eng., 23 (5) (1968) 204-215; 24 figs., 2 tables, 8 refs. Machining-type wear, similar to that observed on journal and thrust runner surfaces in service, was reproduced in the laboratory by a test in which abrasive particles were added to the oil entering the test bearing. Tests were run on several materials to determine their susceptibility to such wear. The effect of two oils, one with a mild e.p., the other without the e.p., is shown. In some instances the debris produced by the machiningtype wear phenomena caused the damage to become self-propagating. A clean lubricant, free of abrasive particles, did not cause machining-type wear in a material found to be highly susceptible to such wear. Wear of Unlubricated Sliding Contact.

Steel

Surfaces

in

D. G. Powell and S. W. E. Earles, ASLE Trans., II (2) (1968) 101-108; 7 figs., 16 refs. Observations have been made of the wear from a SAE 1113 steel pin specimen rubbing on a SAE I I 13 steel disk in a normal laboratory atmosphere in relation to normal load (0.5-10.4 lb.), sliding speed (21-188 ft./set), sliding distance and track history. As a function of sliding distance, three regions are observed; (i) initial severe wear, (ii) mild wear resulting from the formation of oxide layers on both the pin specimen and transferred particles adhering to the track, (iii) a milder wear, due to to the attainment of a uniform track condition. The wear rate measured in (ii) is observed to be proportional to normal load for constant (normal load)& x (sliding speed) provided that the magnitude of this parameter is insufficient to cause periodic removal of the surface film. This conclusion is shown to be compatible with earlier theoretical predictions when the presence of an oxide layer was pre-supposed. Unlike the coefficient of friction which is primarily determined by the pin surface condition only, the pin wear rate depends on the conditions of both the pin and track surface. Surface Periodic between

Temperature and its Relation to Changes in Sliding Conditions Unlubricated Steel Surfaces. Wear, 12 (1968) 299-305