| 摘要 |
Steels of particular compositions which, because of their sulphur contents and of the composition of the oxidised inclusions, are particularly suitable for screw-cutting and machining at high speed using carbide or ceramic tools. The steels contain, in weight %: C - 0.05 to 0.45 % Mn - 0.80 to 1.65 % Si - 0.10 to 0.35 % P - max. 0.030 % S - 0.050 to 0.12 % and the compositions of their oxidised inclusions are, in weight %: Al2O3 - 15 to 50 % SiO2 - 20 to 60 % CaO + MnO - 15 to 50 %. Despite the presence of sulphur, these steels retain good mechanical characteristics. |
