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).
Page describing metal treatment processes such as phosphorizing and ebony black finishing.
| Identifier | ExFiles\Box 38\6\ Scan180 | |
| Date | 30th May 1919 guessed | |
| -2- the furnace burners and to the pipes used for blowing the saw-dust from the treated articles. The oil should be cooled by pumping it throught coils immersed in cold water. PHOSPHORIZING. Rudge-Whitworth's Patent Phosphorizing Process - suitable for steel or cast iron. Bright steel or cast iron parts polished, pickled, barrelled, sand blown, machined or finished bright are immersed in a boiling, dilute, neutral, or nearly neutral, solution of hydric Phosphate of iron for about one hour, then removed, washed in nearly boiling water, dried by swinging or blowing air on to them and dipped, whilst still hot in rape oil, and allowed to drain. If the work is very greasy or oily, swilling in paraffin before boiling is desirable, but a thin film of oil or grease comes off automatically during the boiling process. The Hydric Phosphate of iron solution is made by pouring 1 vol. Phosphoric Acid mixed with three vols. of hot water on to excess of iron turnings, borings, or drillings (steel or cast iron), allowing to stand for 16 hours and diluting with vols. of water. Dilute solutions of Sulphurous acid and Sodium Bisulphite are added in prescribed amounts from time to time, to maintain the solution in the right degree of neutrality and freedom from oxidation. The coating consists of close and adherent phosphate of iron which, when impregnated with oil, celluloid or other suitable composition imparts a high degree of resistance to rusting influences. The oil blacking process is suitable for steel. The heat-blacking process is suitable for cast iron but not so suitable for steel. The phosphorizing process is suitable for both cast iron and steel. The surface of steel oxidizes more readily than cast iron, so for steel the furnace atmosphere should be far less oxidizing than for cast iron. Excess of air or temperature above 730°C leads to blistering of the coating on steel articles. EBONY BLACK FINISH. This is obtained by phosphorizing and drying as above. instead of being dipped in rape oil. The articles are then rubbed or sprayed with a thin coat of raw Linseed oil and stoved for one hour at 300°F.{Mr Friese} One coat of Pinchin Johnson's rubber first coating enamel is sprayed on and stoved for two hours at 250 to 300°F.{Mr Friese} One of the virtues of the phosphorized coating is the absorbent action, whereby it becomes permeated and reinforced by a matrix of firm gum and the surface of the article is protected uniformly all over. If raw Linseed Oil is applied to a steel surface it collects and runs into grooves resulting in a film which is not uniform. | ||