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).
The hardness testing of a cylinder liner and its properties compared to carburised nickel steel.
| Identifier | ExFiles\Box 154a\1\ scan0129 | |
| Date | 1st January 1929 guessed | |
| 2. gradually changing layer of 0.012" approximate depth which merges almost imperceptibly with the core. It is impossible to test the case satisfactorily for hardness as the depth of the uniform outer layer is in-sufficient for the standard Rockwell test, and the specimens are quite unsuitable for the Scleroscope. There is little doubt, however, that it is definitely harder than the surface of carburised nickel steel. It will be remembered that we sent to you with our memo. M629, an extract of a paper by Eaton of the Molybdenum Corporation of America, in which our opinion as to the value of the diamond penetration for determining the fitness of the nitrided case for service, was confirmed. It is of interest, therefore, to note that the surface of this cylinder liner does not crack up under the Rockwell diamond penetrator test, but behaves exactly as a thin cased nickel case-hardening steel. i.e., the case will deflect, which causes it to give an incorrect Rockwell reading, but will not crack or flake. In consideration of our past experience with carburised nickel steel and other hard surfaces, this liner appears to be very good indeed, and the process used for its production a promising one. One of our further tests will be to nitride a piece of this material in an endeavour to reproduce this satisfactory surface. H1. HE | ||