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).
Comparison of nitrided versus carburised materials for differential crown wheels, focusing on case depth and core hardness.
| Identifier | ExFiles\Box 154a\1\ scan0146 | |
| Date | 15th March 1929 guessed | |
| - 3 - contd. With regard to the use of the process on, for example, differential crown wheels, it is important to consider when comparing with the carburised material that the nitrided case is much less in total depth and has probably a greater hardness "taper". It may, therefore, require greater core support if the load is to remain the same. You are probably aware that it has been found necessary to stiffen the core of this gear to prevent deflection of the case, which normally, is approximately 0.040" thick. The effective depth of the nitrided case is probably not more that 0.010" to 0.015", as compared with 0.035" on the carburised material. The above figures are, of course, based on the samples of nitrided steel with which we have dealt up to the present. The core hardness of the Aubert & Duval bars which we tested was only 217 - 255. Table -- See Reference Sheet. H1. He | ||