Micro-examination report on a special nitrogen case-hardening steel from a Hispano-Suiza half cylinder liner.
| Identifier | ExFiles\Box 154a\1\ scan0128 | |
| Date | 1st January 1929 | |
| Micro-Examination Report. X4469 M635. Hs. {Lord Ernest Hives - Chair} H18/EA1.1.29. Laboratory. c to R. {Sir Henry Royce} By. {R.W. Bailey - Chief Engineer} c to Rg. {Mr Rowledge} Wor. {Arthur Wormald - General Works Manager} Re Special Steel for Nitrogen Case-Hardening. The half cylinder liner from Messrs. Hispano-Suiza has now been examined and its principal characteristics determined. Analysis of Core. Carbon -------- 0.46 % Manganese ------ 0.46 % Nickel -------- 0.81 % Chromium ------ 1.35 % Molybdenum } --- Negligible. Vanadium } Phosphorus ----- 0.030% Sulphur -------- Negligible. Silicon -------- 0.10 % Aluminium ------ 1.53 % Hardness of core ---- 238 Brinell. The composition differs very considerably from that of the material used for the test pieces referred to in our report M626. The higher aluminium content and the presence of nickel are the principal points of difference. From the information we have been able to collect with regard to nitrogen case-hardening, it would appear to be a particularly suitable steel for the purpose, especially as it contains nickel, which we believe is a desirable constituent. Micro-examination showed that the case was 0.021" deep. The most interesting point about it was the very gradual change from case to core. This is a great improvement on the test pieces originally supplied by Firth-Derihon, in which the change was quite sharp. In the present instance there is also an absence of the extremely brittle outer surface layer, which tended to flake off the first specimens. It is quite difficult to do more than crack the surface of the liner even at a sharp edge, and there is no tendency to flake. The case consists of an outer layer of approximately 0.009" depth which is of very great hardness, and then a | ||
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).