Particle tribology

Particle tribology

Viscosity measurements go metric In March 1976 the Institute of Petroleum Standardisation Committee into a rather more detailed description of ferrog...

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Viscosity measurements go metric In March 1976 the Institute of Petroleum Standardisation Committee

into a rather more detailed description of ferrography.

made to relevant ISO, DIN, MIL, and British Standards.

recommended that the adoption of Celsius reference temperatures for viscosity measurements should be completed by March 31st 1977. The 1977 edition of the IP standards for Petroleum and Its Products is unlikely to be published before March 1977, but a preprint of the method has been published in the February issue of Petroleum Review.

The paper concludes that particle tribology, in addition to providing information for the fundamental study of friction, wear, and lubrication, enables a prognostic approach to failure prevention and can aid the design of advanced machinery. It is also suggested that particly tribology may make a significant contribution in the opposite direction: in efficient material removal in metal forming operations. NEL, East Kilbride, Glasgow, Scotland

For further information contact Stanhope-Seta Ltd, Station Road, Chertsey Surrey KT16 8BG, UK

The new standard, IP 226/77, corresponds with the American Society for Testing and Materials specification (ASTM D 2270). The tables and equations provide a method of calculating the viscosity index of a lubricant from its kinematic viscosity at 40 and 100°C. Tables are provided for oils with kinematic viscosities of 2.070.0mm 2/s (cSt) at 100°C, and equations for calculating basic values for oils with higher viscosities. For further information contact The Institute of Petroleum, 61 New Cavendish Street, London W1M 8AR, UK

Particle tribology In October 1975, D. Scott presented a paper on particle tribology as the chairman's address to the Tribology Group of the Institution of Mechanical Engineers. The National Engineering Laboratory has issued this paper as an NEL report. The paper begins by noting that much of the research into wear problems has been directed towards the study of surfaces in relative motion, their interactions, and the effects of lubricant and environment. Comparatively little attention has been given to the products of wear. It is suggested that particle tribology, the study of the wear debris, can indicate the mechanism of their formation and yield specific information on the state of the surface. Wear mechanisms are briefly reviewed, giving a theoretical background on the development of wear particles. Techniques for examination, identification, and assessment of debris and lubricant contaminants are outlined, leading

Salt bath surface treatments Selection of surface treatments is far

from easy. A wide range of processes are available, with a number of variations on each theme. ICI have produced a wall chart on their salt bath processes which is claimed to be "a real contribution to the problem of selecting the right heat treatment." The wall chart lists the salts used in ten different processes, giving the effect on the component, the 'benefits', treatment temperature, and typical applications. Some equivalents for high speed steels and carbon steels, and British specifications for wrought steels with overseas equivalents are also given. Free copies of the wall chart can be obtained from Cassel Heat Treatment Specialists, ICI Mond Division, PO Box 216, Witton, Birmingham, B6 7BA, UK

Testing petroleum products; Continuing development of specification tests for petroleum based products has been paralleled by an ever increasing range of test equipment. Stanhope-Seta have recently published an up-dated catalogue describing over I00 test methods. The catalogue describes equipment for testing in accordance with methods laid down by the Institute of Petroleum and the American Society of Testing and Materials. Reference is

Standards on petroleum products Parts 23-25 of the 1976 Annual Book of the American Society of Testing and Materials contain 395 standards on petroleum products and lubricants. Many of the standards covered are not relevant to the tribologist. Over 20% of the standards are new, revised, or changed in status. New tests include tests for quenching time of heat treating fluids, fuel diluent in used diesel engine oils, and life performance of automotive wheel bearing grease. Copies of the books (Part 23: $31 ; Part 24: $31; Part 25: $25; plus shipping charge) are available from ASTM, 1916 Race St, Philadelphia, Pa 19103, USA

Piston rings To assist the rationalisation of metric sizes, materials, and other characteristics of piston rings, the British Standards Institute have published BS 5341 'Piston rings up to 200mm diameter for reciprocating internal combustion engines'. The specifications are based on the German DIN standards for piston rings for automotive applications. Part I 'Designs, dimensions, materials, and designations for single piece rings' specifies nominal diameters, radial thicknesses, widths, closed gaps, forces, surface textures and other design features such as surface treatments, coatings and inlays. Designation coding and applications are also covered. The difficulties in defining attainable quality levels in commercial manufacture of piston rings is well known. In some instances, for examples, small defects will not affect performance: other defects are obviously unacceptable. Part 3 'Quality requirements' seeks to quantify these aspects and to give guidance to both suppliers and

TRIBOLOGY international April 1977

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