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).
Comparing the composition and properties of different valve steel materials at high temperatures.
| Identifier | ExFiles\Box 154a\1\ scan0073 | |
| Date | 8th June 1928 | |
| H.R. C.R. C. Hs. {Lord Ernest Hives - Chair} C. Rg. {Mr Rowledge} X474 BY9/C.8.6.28. TESTING VALVE MATERIAL. --------------------- Referring to H11/EA.4.6.28. it seems very difficult to reconcile the results arrived at with those published by Mr. P.B. Henshaw of Kayser Ellison's, and Dr. Hatfield of Firths, in their papers on the properties of valve steels at high temperatures. The carrying out of tests on steels at high temperatures is admittedly full of difficulties, and where instead of a simple test piece an actual valve is introduced, it would appear that the difficulties are multiplied considerably from the point of view of obtaining accurate and consistent results. In considering the results arrived at by the two people referred to above, one certainly would not expect to find that Firths H.R Crown would be any different from K.E. D.T.D.49 steel since their compositions are so very similar, as will be seen from the analysis given below :- | | K.E.965. | High Nickel Chrome Tungsten. | |---|---|---| | Carbon | .4% | .42 to .48% | | Manganese | .6% | .5 to .8% | | Silicon | 1.5% | .6 to .9% | | Nickel | 12 - 13% | 9 to 10% | | Chromium | 12 - 13% | 13 to 14% | | Tungsten | 2% | 3 to 3.5% | and further one would not expect from the results in question to find that our S.L.V. steel crept less than the high nickel chrome tungsten steel. I am giving below figures for maximum tensile, elongation % and reduction in area % at different temperatures for the different steels, and from these published figures it would appear that our S.L.V. steel is more likely to creep | ||