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).
Method for selective nitride hardening of steel components using tinning as a mask.
| Identifier | ExFiles\Box 154a\1\ scan0117 | |
| Date | 23th November 1928 | |
| X2469 R c.Hs. {Lord Ernest Hives - Chair} ---------------- BY20/G.23.11.28. NITRIDE HARDENING. ------------------ Referring to R1/M22.11.28. it is possible to prevent the penetration of the nitrogen into the steel by tinning the material in the positions not required to be hardened when made to the finished sizes. Immediately after tinning, the surface tin is scrubbed off with a wire brush, but there is a microscopic surface layer of iron tin alloy left which prevents the penetration of the nitrogen. We are only hardening the valve gear cam follower on the surfaces required hard, the threads will be left soft by the above process. BY. {R.W. Bailey - Chief Engineer} | ||