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).
Analysis of slag content and microstructure in various steel shafts and crankshafts.
| Identifier | ExFiles\Box 63\4\ scan0131 | |
| Date | 25th September 1930 guessed | |
| -3- Nitralloy Shafts. The slag particles were numerous, but were not found in the form of strings or streaks, and were fairly evenly distributed. The micro-structure of the case appears unusual. Below the usual thin white layer, it has most of the characteristics of the core structure, and the junction between core and case was vague. We have only once previously seen a case with a coarse structure and this we found on a part which had not been heat-treated prior to nitriding. Other nitrided cases which we have examined have had a fine-grained structure and also a fine-grained fracture. Vickers Super "V.N.C.A." Crankshafts. The slag content of this material and the macro-structure were normal. See "General Notes." 5% Nickel Case-Hardening Steel Shafts. Spec. 2072 (S/ZN). The slag content was normal. The micro-structure of the case was good, and quite free from massive carbide. Shafts marked "S/ZNCR." Shaft No.1. had a moderate grain size but Shaft No.3. had a coarser structure which indicated overheating. The slag content was normal. General Notes. Except where otherwise stated the structures are typical of large bar material. Contd. | ||