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).
Micro-examination report on failed cadmium plated small screwed parts, detailing chemical composition and hardness.
| Identifier | ExFiles\Box 30\6\ Scan071 | |
| Date | 18th January 1929 | |
| X1360 Micro-Examination Report. M639. By.{R.W. Bailey - Chief Engineer} [Strikethrough] H14/EA18.1.29. Laboratory. c to Hs.{Lord Ernest Hives - Chair} Re Cadmium Plated Small Screwed Parts. Further to our reports M631/2/3. We have examined the two original parts which failed on the engine. Unfortunately, the screwed ends which broke off were not available, so our examination was limited with respect to the threads, only two of which remained on each part. Analyses :- No.1. Carbon ----- 0.29 % Manganese --- 0.60 % Nickel ----- Traces Phosphorus --- 0.031% Silicon ---- 0.08 % Sulphur ---- 0.020% No.2. ----- 0.31 % ----- 0.60 % ----- Traces ----- 0.029 % ----- 0.08 % ----- 0.020% This agrees with Spec.201D. Brinell hardness :- No.1. ---------- 182 No.2. ---------- 191 Under the microscope we found that the grain size and structure were quite satisfactory, as will be seen from the attached photomicrograph No.A613. No excess of impurities was found. Excellent bends and fractures were obtained (see sample herewith). The depth of the cadmium coat was 0.0007". It would not appear that the material has any unusual features. Hl. IHC | ||