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).
Laboratory report detailing corrosion tests of four different 'high pressure' axle oils on various metal specimens.
| Identifier | ExFiles\Box 114\1\ scan0186 | |
| Date | 31th March 1939 | |
| 1015 Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} HL./BPS. 1/JM.{Mr Morley} 31.3.39. Laboratory Report 4802. Re: Axle Oils. Your ref. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} 5/JH. 14.2.39. Herewith results of our examination of the four samples of "high pressure" lubricants which you submitted. The corrosion tests were carried out by half immersing polished pieces of phosphor bronze, aluminium bronze, mild steel and stainless steel, in each of the oils @ 120°C., for a period of 24 hours. At the end of this period, the pieces were removed, examined, and results recorded in tabular form. The deposits adhering to the test specimens were detached, weighed, and the amounts per unit area of surface computed; the figures obtained are only approximate, but are sufficient to serve as a guide for comparison of the relative amounts of deposits formed. It was found, on analysis of the deposits, that those formed on the bronze specimens by GX, Wakefield's and T.E.X. oils, consisted of chlorides and sulphides of copper and that those formed on the steel specimens by the same oils, consisted of chlorides and sulphides of iron; the amounts of chlorides in the deposits from the T.E.X. oil were small compared with the sulphides present. The deposits formed by Hypoid oil, also consisted of chlorides and sulphides of the metals comprising the test specimens, but in addition, they contained lead sulphide, the latter having arisen from decomposition of a lead compound, originally present in the oil. The phosphor bronze was severely corroded by GX, Wakefield's and Hypoid oils, but very little by T.E.X. The former three oils caused no pitting or irregularities in the surfaces of the aluminium bronze and the two steels, but, since the major constituents of these materials were found in the deposits therefrom, it was evident that corrosion had taken place, apparently of a very uniform nature. In the case of T.E.X. oil, no serious corrosion was discernible with respect to the aluminium bronze and steel, the slight discoloration of the bronze and mild steel consisting of firmly adherent sulphide films which would probably protect the material in practice. In addition to the deposits formed on the test specimens, it was observed that heating the oils @ 120°C. for a period of 24 hours, resulted in a large amount of deposit being | ||