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).
Visit to Messrs. Fescol to discuss chromium deposition processes for engine parts.
| Identifier | ExFiles\Box 142\4\ scan0146 | |
| Date | 14th June 1935 | |
| To Hs.{Lord Ernest Hives - Chair} & RHC.{R. H. Coverley - Production Engineer} 1203 Hs{Lord Ernest Hives - Chair}/Smth.3/MJ.14.6.35. VISIT TO MESSRS. FESCOL. During a visit to Messrs. Fescol yesterday the following points were discussed with their Mr. Wilson. With regard to Merlin rockers Mr. Wilson said he would be very surprised if we had trouble due to the chromium scaling off. He admitted that there was a tendency to scale on surfaces subject to heavy impact, but did not think the rockers would give trouble if suitably prepared. The preparation he recommends is that we should grind the pad profile .004 undersize and harden the surface to the same extent as we should do if we were to use the rocker without chromium deposition. All corners should be radiused by at least .010. He will then deposit a layer .006 thick, after which we should grind back to size. Chromium deposits more than .006 thick are not recommended since the metal becomes crumbly after this limit. Fescols are developing a new method which they intend to call the "Michrom2" process whereby the thickness of .002" is deposited, after which no further grinding is required. This may be more suitable for our job. We discussed the question of abrasion between metallic surfaces and Mr. Wilson agreed with our view that hardness alone was not the vital factor. He quoted tests which show that chromium is of value where rubbing occurs, not only because of its hardness, but also because of the 'slipperiness' of the surface. We were told that Talbot's have their camshafts and the pins and journals of their crankshafts Fescolised. To fescolise the cam rather than the rockers seems to be doing the job the wrong way round. Mr. Wilson was very anxious to Fescolise a crankshaft for us. He would do so free of charge if we would promise to test it. He says that the wear of a shaft running in white metal bearings is quartered when the surfaces are Fescolised, but he has no experience of Fescolised journals running in lead bronze. Hs{Lord Ernest Hives - Chair}/F.{Mr Friese} H.{Arthur M. Hanbury - Head Complaints} Smith. | ||