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).
Procedures for producing and heat-treating melts, including furnace types, hardness tests and the use of flux.
| Identifier | ExFiles\Box 116\2\ scan0109 | |
| Date | 1st November 1938 guessed | |
| (6) The normal practice is to produce a melt of 200 lbs, which is produced in a Morgan Bale-out furnace with a Morgan Crucible. The melt is produced and consumed in approximately three hours. (7) Heat-treatment should be done in the rough. (so that Brinell hardness tests can be obtained with a load of 500 kilos. with 10 mm. ball). 12 hrs. at 180°C. should be sufficient to get a hardness figure of 55 to 75. A second heat-treatment i.e. of 12 hrs. at 180°C. is permitted if bearings are slightly below 55 on first heat-treatment since longer ageing is no disadvantage in that case. The furnace or oven used should be of the air circulation type - similar to the 'Birlec' seen during your visit. (8) Flux is not normally used. When occasion demands, such as the remelting of bearings after machining, which may be impregnated with oil, the melt is cleaned when molten at the rate of 2 ozs. per 100 lbs. RM{William Robotham - Chief Engineer}/CTT. | ||