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).
Laboratory analysis of a failed Condor Crankshaft after an endurance test.
| Identifier | ExFiles\Box 76\3\ scan0102 | |
| Date | 30th September 1919 | |
| copy R.{Sir Henry Royce} c. to EH. c. to BN.{W.O. Bentley / Mr Barrington} H18/EB30.9.19. Laboratory. Re Condor Crankshaft that broke after about 110 hours endurance test, received this morning. Analysis. Carbon .38 Manganese .48 Chromium .67 Nickel 3.39 Silicon .33 Sulphur .034 Phosphorus .025 From the analysis it appeard that this steel is higher in carbon than usual, it is also high in silicon and the chromium is on the high side also. The composition is more similar to that of the crankshafts that gave indications of hair lines in the past. The silicon appears to be on micro examination considerably in the slag form and there is also evidence of segregation, which is confirmed by sulphur prints. The latter indicated considerable manganese sulphide in rather larger particles than usual. The Brinell hardness is 302, but where it has hammered owing to fracture it has gone up to a higher figure, and is much more difficult to saw. Martenzite is evident in be steel and it is possible that this has made it more liable to fatigue fracture. Micro photographs and sulphur prints to follow. HCH. | ||