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).
Heat treatment process for the Phantom III chassis induction box heater to prevent radiator silting and corrosion.
| Identifier | ExFiles\Box 94\3\ scan0156 | |
| Date | 20th March 1937 | |
| RHC.{R. H. Coverley - Production Engineer} c.Rm.{William Robotham - Chief Engineer} c.Hbr. c.RHC{R. H. Coverley - Production Engineer}/Mr.Pendlebury. c.E.Dept. 340 Order Ry/500 BY/EM.10/J.20.3.37. P.III CHASSIS INDUCTION BOX HEATER. We understand that complaints have been received with regard to the Silting up of P.III Radiators and that part of the deposit is found to be iron. We have had previous experience of this trouble and it would appear that the products of corrosion from aluminium combined with iron form a kind of a type of silt which may clog up restricted areas in the radiator. On the previous occasion we were able to minimise the trouble to a considerable extent by giving the cast iron parts in the water system an oxide film which was definitely resistent to corrosion attack. Since we are now again troubled with the same problem, we consider that the induction box heater part number E.88029 which is the only cast iron part in the water system, should be given this oxide coating. The coating is given by suitable heating of the parts at a temperature of 520°C. and is very much more efficient if a jet of steam is played into the furnace during the heating operation which should be maintained for at least one hour. We consider this is of sufficient importance to have all our stock of induction box heaters treated in this manner and also those on chassis which are in the Test Dept. providing we can carry out the heat treatment without undue distortion. We shall be glad if you will kindly arrange to have one or two finish machined parts treated in this manner in order to check whether the distortion is too great to be corrected. Will E.Dept. also kindly add this treatment to our detail drawings and the treatment should be applied to all castings which have not reached the finished state. We will await RHC{R. H. Coverley - Production Engineer}'s report before we definitely instruct finished castings to be given this treatment. BY/EM. | ||