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 report on the hardness, microstructure, and defects of a Phantom III Front Hydraulic Damper central tube.
| Identifier | ExFiles\Box 96\1\ scan0361 | |
| Date | 19th December 1938 | |
| M.1756. 361 By.{R.W. Bailey - Chief Engineer} from H1/EJW. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} H1/EJW. 1/JM.{Mr Morley} 19.12.38. Laboratory. Phantom III - 3BT.{Capt. J. S. Burt - Engineer}55 - Front Hydraulic Damper Central Tube - Your ref. By.1/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 6.12.38. ------------------------------------------------------ The hardness of this tube at the brazed end was 172, away from the brazed end it was 161. This difference is probably explained by the effect the brazing operation has had on the micro structure. Before brazing, the structure was as shewn in photomicrograph M.1756/1. It will be noted that the cementite is in the spheroidal condition. After brazing, the pearlitic structure was restored, as shewn in photo. M.1756/2. Fracture tests indicated that in the original condition there was a tendency to brittleness in the cell walls, which appeared as brilliant facets in the fracture, see sample herewith. This condition was not found in the brazed section. In addition to this evidence of unsuitable annealing, we found that the inner surface of the tube was decarburised and contained longitudinal oxidised seams, such as are illustrated in photomicrograph No. M.1756/3 (part of one is also shewn at the top of M.1756/1). The deepest one shewn in the photo. is approximately .008" deep. H1/EJW. | ||