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).
Report from the National Physical Laboratory on a corrosion inhibitor test.
| Identifier | ExFiles\Box 150\3\ scan0367 | |
| Date | 24th July 1937 | |
| NATIONAL PHYSICAL LABORATORY (METALLURGY DEPARTMENT) REPORT Abstract of (results obtained in) Tests of a Corrosion Inhibitor submitted by Messrs. Newton, Chambers & Co., Ltd., Grand Buildings, Trafalgar Square, London, W.C.2. Authority for Test: Letter dated 20:1:37. Two cast-iron pots, A and B, 21.5 cm. high, 16.5 cm. diameter, were filled to within 1 cm. of the brim, A with tap-water, B with tap-water containing 1/80 of its volume of the inhibitor. In each pot, weighed metal rods, about 18 cm. x 1 cm. diameter stood on end, spaced by a glass cage to leave room for a nickel paddle 10 cm. wide. By day, but not at night, the pots were heated to 80° + 5°C. and the paddle rotated at 5 r.p.m. Covers of sheet rubber minimised evaporation. Water was added as required to maintain the level. | Inspection Stage | Pot | Mild steel drawn rod. | Cast iron turned. | Copper drawn rod. | Brass drawn rod. | Solder over brass. | Y-alloy wrought, heat-treated, turned. | Cast iron pot. | Liquid in pot. | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | First inspection after 8 days of immersion—48 hours' heating. | A | blackened | blackened | trace of rusty scale | trace of rusty scale | trace of rusty scale | 5-6 small efflorescences | slight rusting | much rust settled, 400 ml. evaporated. | | | B | bright with oily film | bright with oily film | bright with oily film | bright with oily film | bright with oily film | bright with oily film | oily film | 50 ml. evaporated | | Second inspection after 18 days of immersion—100 hours' heating | A | black with signs of pitting | black | some rusty scale | some rusty scale | some rusty scale | dull, with rusty scale | rusting | 950 ml. evaporated | | | B | bright | fairly bright with black oily streak | nearly free from scale | no scale | no scale | bright with a few white spots | oily film | 300 ml. evaporated | | Third inspection after 43 days of immersion—198 hours' heating. | A | black with cap and streak of rust | dull black with large rusty patches | thin film of rusty scale | thin film of rusty scale | thin film of rusty scale | thin film of rusty scale, 4 white nodules | rusty | 2 l. evaporated, thick black sediment | | | B | slightly dulled, oily | bright with 3 small patches of rust, oily | bright and oily | bright and oily | bright and oily | oily, white nodules very dense near bottom end | oily | 750 ml. evaporated, very slight sediment | | Final inspection after scrubbing | A | much sooty oxide removed, one pitted patch | much sooty oxide removed: no pits | dull | slight scale remained | dull | grey with a few white spots | rust near top | ignited sediment 5.23 gm. | | | B | slightly dulled | 3 black patches | fairly bright | fairly bright | bright | pits and protuberances in lower half | very little rust | ignited sediment 0.46 gm. | | Change in weight mgm/cm² | A | 9.49 loss | 5.61 loss | 0.03 loss | 0.24 gain | 0.05 loss | 0.26 loss | - | - | | | B | 0.29 loss | 1.21 loss | 0.29 loss | 0.42 loss | 0.08 loss | 1.64 loss | - | - | Strips of black rubber hose-pipe suspended in the pots after the second inspection were little affected in either A or B, but in B the rubber had become slightly tacky. On the nickel paddle in A numerous minute nodules formed: that in B showed only a few slight spots. F.{Mr Friese} E.{Mr Elliott - Chief Engineer} SMITH, Director. S. L. ARCHBUTT, For Superintendent, Metallurgy Department. | ||