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).
Micro-examination, analytical, and mechanical test report on the case-hardening of steel by the nitrogen process.
| Identifier | ExFiles\Box 154a\1\ scan0101 | |
| Date | 10th November 1928 | |
| X4469 Micro-Examination, Analytical and Mechanical Test Report M626. By. {R.W. Bailey - Chief Engineer} c to Mr. [crossed out] c to Mr. [crossed out] c to Mr. [crossed out] c to Hs. {Lord Ernest Hives - Chair} H11/EA10.11.28. Laboratory. RE THE CASE-HARDENING OF STEEL BY THE NITROGEN PROCESS. A supply of a special chromium-aluminium-molybdenum steel was submitted by Messrs. Firth-Derihon. This you had machined into the following mechanical test bars :- Seven Tensile Test Bars. Four Stanton Test Bars. Four Upton-Lewis Test Bars. The material had already been fully heat-treated by Messrs. Firth-Derihon, and the finished test bars were returned to them for the final case-hardening by the nitrogen process for, we understand, a period of fifty hours. The case-hardened bars were then submitted to us again for test. We found the analysis of the special steel to be as follows :- Carbon --------- 0.40 % Manganese ------ 0.52 % Aluminium ------ 0.97 % Chromium ------- 1.80 % Molybdenum ----- 0.24 % Silicon -------- 0.28 % Sulphur -------- 0.035% Nickel --------- Nil. Phosphorus ----- 0.022% The results of the mechanical tests are given below:- Tensile Tests. The figures in Table I were obtained on a bar tested as received from Messrs. Firth-Derihon in the first instance, that is, fully heat-treated but not case-hardened. Table I. Test Bar No. Ult. Stress. Yield Point. Elong. % on 2" R.A.% Brinell Hardness. FD {Frank Dodd - Bodies} 12 60.8 51.8 22.5 58.9 285 The test figures in Table II were obtained on bars fully heat-treated and case-hardened by the nitrogen process. Table II | ||