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 page detailing the development and testing of a high-strength, low-carbon cast iron alloy composition.
| Identifier | ExFiles\Box 132\1\ scan0023 | |
| Date | 18th April 1927 guessed | |
| -10- of the weakness of the composition employed. As previously stated the use of higher carbon alloyed cast iron materially assists in the obtaining of sound sections, yet to obtain higher ultimate tensile strength and fatigue strength it becomes a necessity to employ lower carbon compositions as compared with ordinary cast iron standards. A systematic attempt was made to evolve a high strength alloy with the best casting characteristics such as would reduce foundry difficulties. It was found that to do this, experiments would have to be confined to these alloy compositions which on solidification had no primary graphite. Further, the results were highly successful from a purely metallurgical point of view, for unprecedented strength was obtained, but up to the present no practical method of casting the alloyed cast iron to give absolute solidity of sections without adopting the objectionable practice of providing feeding heads of metal over heavy pieces of the design. A consideration of the results obtained from many combinations of elements which in themselves are too numerous to publish in this effort, singles out one alloy of outstanding importance. The composition of it is as follows:- Total Carbon ... 1.74% Silicon ... 0.62% Manganese ... 0.63% Sulphur ... 0.05% Phosphorus ... 0.05% Nickel ... 1.94% Molybdenum ... 0.64% The following tests were carried out from Rectangular Blocks, 8" x 2½" x 2½", Sawn in eight pieces, and the following heat treatment given:- 9 hours at 1000°C., Cooled to 950°C. 8 " " 950°C., " " 900°C. 7 " " 900°C. Box and test pieces cooled in air. The eight test pieces were reheated to 900°C., for one hour, transferred to a furnace at 650°C., and held at one hour, and then | ||