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).
Visit to Harvey, Illinois, concerning the forging process and steel quality for Merlin engine cranks.
| Identifier | ExFiles\Box 178\2\ img104 | |
| Date | 5th January 1940 guessed | |
| Notes on Visit to Harvey, Illinois. Page 2. It is the breakdown die which determines grain flow, and American forging practice demands that the forging from the breakdown shall actually slip part way into the finishing die, when laid in place for finish forging. The finishing then becomes practically a sizing operation. The Merlin crank is finished in a 15000# hammer, whereas a 25000# hammer is being built for Vickers at Chambersburg, presumably for doing the same job. Generally, the forging job is going as well as could be expected, although slightly delayed, due to the unfamiliarity of the design, rather than any difficulties with the steel. Steel. The first heat of steel has now been fully examined and has proved excellent. The Magnaflux tests show better results than the "optimum" Army Air Corps tests shown us by Harold Wood on our first visit. (Lessells will send full report). This perhaps does not prove that "inclusions" will not show up on final visual inspection after nitriding, but it does show that the steel is as clean as any alloy steel previously made in this country. Morris, of Republic, who was present, is quite pleased with the results. But, as he says, this result may be pure luck. He needs to confirm his results by three more heats. If these are equally successful he can regard the problem of making clean VCM steel as completely solved as far as Republic are concerned. More Expl. Heats. It was proposed therefore that he should go ahead with three more heats, each from a 25 ton furnace, reproducing the composition of the first heat as closely as possible. Otherwise, if we wait for the approval of the first 50 forgings from England, which can scarcely be given before late March or early April, the job will have to be taken up over again, and considerable further delay is likely to occur. To further speed up the job as far as possible, it is proposed to send a couple of the first crank forgings over by plane, if this can be arranged. It is further proposed to forge each of these heats individually as they arrive in the W.G. plant, so as to form three separate "runs" in the Harvey plant. This will be of assistance in getting the forging practice standardised. After this preliminary work, which will give us in all about 350 forgings, there seems no reason to doubt that the remaining 1650 | ||