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).
Methods to prevent corrosion in heater boxes for the Phantom III chassis, including oxide films and the Parkerising process.
| Identifier | ExFiles\Box 94\3\ scan0169 | |
| Date | 13th April 1937 | |
| S7D Please see me Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} C.RHC.{R. H. Coverley - Production Engineer} [stamped and crossed out] C.H. [stamped and crossed out] PHIII Radials 3LO. BY/EM.18/J.13.4.37. Woken Rm{William Robotham - Chief Engineer}/SMD{J. Smedley} GRY{Shadwell Grylls} HEATER BOXES FOR P.III CHASSIS. With reference to memo RHC{R. H. Coverley - Production Engineer}/Gry.{Shadwell Grylls}2/LS.12.4.37, and as discussed with Mr.Steadman, we consider that the question of the corrosion from the cast iron heater boxes can be dealt with in two ways which are as follows :- (1) We can apply the oxide film as previously described but in order to ensure that this oxide film is thoroughly adherent and resistent to corrosion attack, it is absolutely necessary that steam should be injected through the boxes during the oxiding process. This can be carried out by giving the boxes a treatment at 520°C. in the presence of steam. (2) As an alternative, the Parkerising Process is worth consideration, but if the Parkerising process is employed then both the Laboratory and ourselves consider it is absolutely essential that the cooling water should be treated with Sodium Phosphate and that proper instructions regarding the additions of Sodium Phosphate should be issued so that fresh supplies can be added as new water is put into the cooling system. This question of the Phosphate treatment of water has previously been recommended and providing it is properly used, we think that it will be found to be a complete cure for troubles arising out of the corrosion of the water system. We understand that the Works are now giving an ordinary oxide coating to these boxes during the annealing or stress releasing operation, but we would point out that this is not really effective unless it is carried out in the presence of steam. BY/EM. [Signature] | ||