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).
Defining different classes of chassis steels based on their physical characteristics and composition.
| Identifier | ExFiles\Box 142\4\ scan0191 | |
| Date | 12th November 1937 | |
| WHS. [Redacted] Ogilvy/Hives. [Redacted] H.R. [Redacted] C. Rm.{William Robotham - Chief Engineer} [Redacted] R.{Sir Henry Royce} [Redacted] 1203. BY.1/G.12.11.37. CHASSIS STEELS. It has been agreed to define steels finally by their physical attributes only, and in order to prevent misunderstandings arising it is necessary to clearly define what is required when we specify our steels by physical characteristics only instead of as heretofore safeguarding these by adding a carefully limited composition. There are certain characteristics which are due to certain alloying elements, and it is because of this fact that we use straight nickel steels for our bolts, studs and generally high stressed parts, the special quality in Nickel steels is their high ductility and low work hardening rate, whilst on the other hand for wearing parts nickel by itself is impracticable as it seizes up under the slightest provocation. This means that we cannot meet the varying conditions of steel service in a chassis by merely defining the tensile strength which the conditions demand and ignoring composition entirely. The foregoing remarks make clear the necessity for dividing the steels into certain broad classes on composition, which are particularised by the principal alloying element or elements. Following these divisions the correct condition in which to use any one steel can be quite accurately specified by physical characteristics in conjunction with the type of steel. The broad divisions under the heading of composition which cannot be ignored in this connection are :- (a). Straight nickel steels for casehardening. (b). Nickel Chrome steel for casehardening. (c). Straight nickel steels for use in the hardened and tempered condition. (d). Nickel chrome steels for use in hardened and tempered condition. (e). Austenitic steels. | ||