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).
Properties and heat treatment of Molybdenum steel in comparison to Nickel steel.
| Identifier | ExFiles\Box 154a\1\ scan0059 | |
| Date | 21th November 1927 | |
| X1474 BY3/G.21.11.27. C. Bor. G. {Mr Griffiths - Chief Accountant / Mr Gnapp} Pg. C. Hs. {Lord Ernest Hives - Chair} [STAMP: RECEIVED NOV 22 1927] MOLYBDENUM STEEL. ================= Referring to R1/AHO.11.27. Molybdenum Steel shows a definite advantage over 3 1/2% Nickel Steel at from 70 to 85 tons per square inch tensile, but below the minimum figure quoted it has no advantage at all over our standard material. As connecting rods and all our main parts have to be machined, the maximum tensile figure we can work to is approximately 65 tons, at which figure Molybdenum steel shows no advantage over 3 1/2% nickel. In regard to the question of heat treatment raised in the same memo, from the point of view of steel in good condition, one would not expect to do more than what you suggest viz. a {Mr Adams} /- Normalise. b/- Re-heat to just above recalescence point. c/- quench. d {John DeLooze - Company Secretary} /- Temper. but since all steels have a very considerable amount of work put into them under varying conditions, and many of them are maintained at high temperatures for a long period during the production of the billet, the carbide is apt to be thrown out of solution, and if this happens it is admittedly difficult where chromium is present to throw the carbide back into solution regularly throughout the body of the steel. For this reason the double quench advocated by Mr. Pendlebury or the double normalising I myself suggested, are distinctly advantageous inasmuch as the first quench in Mr. Pendlebury's scheme or my first normalising are carried out at a high temperature well above the recalescence point. At a high temperature the reluctance of the steel to take the carbide thoroughly into solution rapidly disappears, but the net result is that if the steel has already a somewhat large structure from having been carried too long at high temperatures, this effect would be exaggerated. The second heating or normalising is then designed to carry the steel only just above its recalescence point and thereby put the steel, which is already in thorough solution into a correct | ||