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).
Laboratory report comparing Izod test results for different steels used in model crankshafts.
| Identifier | ExFiles\Box 63\4\ scan0136 | |
| Date | 10th October 1930 | |
| Y4499. M711R. By.{R.W. Bailey - Chief Engineer} c to Hg. Hs.{Lord Ernest Hives - Chair} (20740/30) H15/EA6.10.30. Laboratory. Re Model Crankshafts. Further to our Report M711. The Izod tests on Case-Hardening Nickel steels, promised in our previous report M711, have now been completed. For the Spec. 2072 steel we have adopted a Brinell hardness of 269 as being the mean of the Specification range. This is also useful for comparison with the Nitralloy Izod tests, which were made on test bars of the same hardness. For the Spec.207C steel a core hardness of 293 Brinell. This corresponds with the hardness of the Tensile and Stanton test bars - see report M711. The material has been tested in two conditions :- "No case" --- Test bars not carburised, but heated in sand for an equivalent period, at the carburising temperature, before being heat-treated. "With case" - These test bars case-hardened all over the surface, including the test notch. The test results are given below, together with the Nitralloy figures for comparison :- Brinell Hardness. Izod Ft. Lbs. With Case. Without Case. Spec.2072 -- 269 --- 23 --- 72 269 --- 24 --- 71 Spec.207C -- 293 --- 15 --- 60 293 --- 13 --- 64 293 --- 13 --- 57 293 --- 15 --- 63 Nitralloy Steel. -- 269 --- 54 --- 65.5 269 --- 55 --- 65.5 H1. HE | ||