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Experimental evaluations of cold-rolling lubricants for strip steel
LITERATURE
AND
the theory of gas-film lubrication. Several calculations are made based upon finite differences for obtaining approximate solutions. A number of explicit, semi-explicit, and implicit difference schemes are examined from the point of view of truncation error, stability, and computational efficiency. Mechanism of Lubrication for Solid Carbon Materials in Vacuum to 10eg mm of Mercury. D. H. Buckley and R. I,. Johnson, ,4SLE Trans., 7 (1964) 91-100. The friction and wear characteristics of various carbon materials sliding on metals and aluminum oxide were determined in vacuum at ambient pressures from 760 to IO-~ mm Hg. The friction and wear expcriments were conducted with a hemispherically tipped carbon rider, under a load of IOOO g, sliding on various disks rotating at a speed of 390 ft. per minute. The results of this investigation show that additional research on carbon in vacuum is warranted. Adsorbed surface films present on both carbons and metal, as well as the presence of oxide on metals, appreciably influenced the friction and wear obtained with carbons in vacuum. Some impregnants were beneficial in reducing friction and wear of carbon in vacuum while others were not.
CURRENT
EVENTS
English
The Two-line Theory in Lubricant Testing (in French) M. Godet, Compt.Rend., 258 (1964) 71-74.
Using the two-line theory developed from gear lubrication data, the author shows that the change in configuration of test specimens (Timken, 4.ball etc.) brought about by wear, causes a variation in the hydrodynamic conditions. This variationcanin turn explainthat: (I) The load carrying capacity (L.C.C.) of a “high wear oil” will be higher than that of a “low wear oil”; (2) The L.C.C. of an oil will decrease as the load increments are increased; (3) The ranking of a series of oils depends on the rate of change of configuration of the test machine employed. (For a summary in
see Engineering,
(1964) Feb. 28, p.
334.) Theoretical
and Experimental Reflexions on Gear Lubrication Research. (in French) %I. Godet, La Machine Outil Fran&se. (193, 194, 195) (‘963/‘964). h review is given of modern
theories and recent experimental data which apply to, or are obtained with, gears. The author also demonstrates that with an I.A.E. type gear tester, only that part of the curve which shows a decrease in load carrying capacity with speed can be obtained. On the Temporary Viscosity Change of Lubricants Subject to Mechanical Shear Stresses Reaching 10s dynes/cma. (in French) F. Lagarde et al., Compt. Rend., 256 (1963) 878-881,
Comparison of the measured thickness of an oil film during a shock with its calculated thickness shows that the viscosity due to the applied shear stresses (10s dynes/cm2) decreases in the course of the shocks. This nonnewtonian behaviour occurs at these very high shear rates even for the most fluid mineral oils. 3.2 Lubricants 3.2.1
The Two-line Theory of Gear Lubrication. (in French) LXI.Godet, Corn@ Rend., 257 (1963) 48-51. It is usually assumed that abrasion and scuffing present two independent performance barriers to gear lubrication. Here, the author contests that point of view and suggests that the shape of the load carrying capacity vs. speed curves obtained from gear test data (Borsoff) can be explained by considering simultaneously a friction and an elastohydrodynamic effect. Further reasoning suggests dividing the load-speed plane into two areas of gear lubrication, one in which abrasive wear is detected, and another in which no wear is found.
469
Special lubricants
Experimental Evaluations of Cold-rolling Lubricants for Strip Steel. R. C. Williams and R. K. Brandt, Lubricution Eng., 20 (2) (1964) 52-56; 3 figs., 2 tables,
3 refs. A series of fatty lubricants and a mineral oil were evaluated on a laboratory rolling mill and a wire drawing tester. Roiling results correlated well with the lubricant viscosity at 210°F. The higher the viscosity the greater the reduction achieved under present rolling conditions. Coefficient of friction data from rolling and room temperature wire drawing results did not correlate. The temperature at which a lubricant failed on elevating its temperature during wire drawing correlated with rolling results. Actual rolling mill tests support the conclusions reached from the laboratory data. A Laboratory Evaluation of Solid FluoroCarbonMaterialsasWire-drawingLubricants. X. F. Gerds and C. B. Ogle, Wive Wire Prod., 38 (1963)
1696-1755.
The effectiveness of several tetrafluoroethylene polymers as wire-drawing lubricants was determined by means of a laboratory test in which these materials were compared with a commercial drawing lubricant. The criteria for comparison were: the maximum obtainable single-pass reduction, and the drawing load required to make a given reduction. Data on the drawing of commercially pure Al, Wear, 7 (1964) 466-475
AND
the theory of gas-film lubrication. Several calculations are made based upon finite differences for obtaining approximate solutions. A number of explicit, semi-explicit, and implicit difference schemes are examined from the point of view of truncation error, stability, and computational efficiency. Mechanism of Lubrication for Solid Carbon Materials in Vacuum to 10eg mm of Mercury. D. H. Buckley and R. I,. Johnson, ,4SLE Trans., 7 (1964) 91-100. The friction and wear characteristics of various carbon materials sliding on metals and aluminum oxide were determined in vacuum at ambient pressures from 760 to IO-~ mm Hg. The friction and wear expcriments were conducted with a hemispherically tipped carbon rider, under a load of IOOO g, sliding on various disks rotating at a speed of 390 ft. per minute. The results of this investigation show that additional research on carbon in vacuum is warranted. Adsorbed surface films present on both carbons and metal, as well as the presence of oxide on metals, appreciably influenced the friction and wear obtained with carbons in vacuum. Some impregnants were beneficial in reducing friction and wear of carbon in vacuum while others were not.
CURRENT
EVENTS
English
The Two-line Theory in Lubricant Testing (in French) M. Godet, Compt.Rend., 258 (1964) 71-74.
Using the two-line theory developed from gear lubrication data, the author shows that the change in configuration of test specimens (Timken, 4.ball etc.) brought about by wear, causes a variation in the hydrodynamic conditions. This variationcanin turn explainthat: (I) The load carrying capacity (L.C.C.) of a “high wear oil” will be higher than that of a “low wear oil”; (2) The L.C.C. of an oil will decrease as the load increments are increased; (3) The ranking of a series of oils depends on the rate of change of configuration of the test machine employed. (For a summary in
see Engineering,
(1964) Feb. 28, p.
334.) Theoretical
and Experimental Reflexions on Gear Lubrication Research. (in French) %I. Godet, La Machine Outil Fran&se. (193, 194, 195) (‘963/‘964). h review is given of modern
theories and recent experimental data which apply to, or are obtained with, gears. The author also demonstrates that with an I.A.E. type gear tester, only that part of the curve which shows a decrease in load carrying capacity with speed can be obtained. On the Temporary Viscosity Change of Lubricants Subject to Mechanical Shear Stresses Reaching 10s dynes/cma. (in French) F. Lagarde et al., Compt. Rend., 256 (1963) 878-881,
Comparison of the measured thickness of an oil film during a shock with its calculated thickness shows that the viscosity due to the applied shear stresses (10s dynes/cm2) decreases in the course of the shocks. This nonnewtonian behaviour occurs at these very high shear rates even for the most fluid mineral oils. 3.2 Lubricants 3.2.1
The Two-line Theory of Gear Lubrication. (in French) LXI.Godet, Corn@ Rend., 257 (1963) 48-51. It is usually assumed that abrasion and scuffing present two independent performance barriers to gear lubrication. Here, the author contests that point of view and suggests that the shape of the load carrying capacity vs. speed curves obtained from gear test data (Borsoff) can be explained by considering simultaneously a friction and an elastohydrodynamic effect. Further reasoning suggests dividing the load-speed plane into two areas of gear lubrication, one in which abrasive wear is detected, and another in which no wear is found.
469
Special lubricants
Experimental Evaluations of Cold-rolling Lubricants for Strip Steel. R. C. Williams and R. K. Brandt, Lubricution Eng., 20 (2) (1964) 52-56; 3 figs., 2 tables,
3 refs. A series of fatty lubricants and a mineral oil were evaluated on a laboratory rolling mill and a wire drawing tester. Roiling results correlated well with the lubricant viscosity at 210°F. The higher the viscosity the greater the reduction achieved under present rolling conditions. Coefficient of friction data from rolling and room temperature wire drawing results did not correlate. The temperature at which a lubricant failed on elevating its temperature during wire drawing correlated with rolling results. Actual rolling mill tests support the conclusions reached from the laboratory data. A Laboratory Evaluation of Solid FluoroCarbonMaterialsasWire-drawingLubricants. X. F. Gerds and C. B. Ogle, Wive Wire Prod., 38 (1963)
1696-1755.
The effectiveness of several tetrafluoroethylene polymers as wire-drawing lubricants was determined by means of a laboratory test in which these materials were compared with a commercial drawing lubricant. The criteria for comparison were: the maximum obtainable single-pass reduction, and the drawing load required to make a given reduction. Data on the drawing of commercially pure Al, Wear, 7 (1964) 466-475