From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Torsion and impact tests on shafts and the investigation of various cast iron alloys for crankshafts.
| Identifier | ExFiles\Box 132\1\ scan0014 | |
| Date | 18th April 1927 guessed | |
| - 2 - Torsion Tests on Shafts. Elastic Limit ... 39.4 Tons. ... 43.0 " Tensile Strength ... ... 57.1 " ... ... 58.0 " Twist at E.L. ... ... 5º and 6º. Twist at T.S. ... ... 20º and 25º. Brinell Hardness No. ... 225 to 321. Impact Tests on Shafts. The shafts must stand a drop of a 50 lbs. weight falling 40" to the flange at the centre of main bearing while supported on the two end main bearings. The report of the mass results from Road [handwritten: Series] indicates that the material stands up well to Torsional Stresses under working conditions without any appreciable wear on the bearings. Experiments carried out with this composition to produce a heavier type of crankshaft such as would be suitable for commercial vehicles, immediately revealed the great difficulty in carrying out the foundry practice which would give soundness in the sections. Equal in importance to the most suitable composition, comes the question of soundness throughout the casting, as the nearer the composition approaches to the steel range, so the difficulty increases of securing this characteristic. In addition the notch effect of the material becomes more and more effective to failure when the material is placed under bending or twisting stresses. It was decided, therefore, consequent upon the realisation of this difficulty to "try out" those materials truly cast iron in composition. To this end twenty six alloys were cast and examined in the early stages of this investigation and were of the following types:- Nickel. Molybdenum. Molybdenum-Chromium. Molybdenum-Copper. Molybdenum-Nickel. Chromium-Copper. Nickel-Chromium-Molybdenum-Copper. With each of the alloy combinations, varying Total Carbon contents were employed to obtain the highest strength characteristics, accompanied by the greatest convenience. | ||