| 摘要 |
A cast iron alloy is made by carburising a low phosphorous cast iron alloy to produce a carbon content of 3.6-3.9% and a nitrogen content of 0.005-0.025%. This also produces a thermal conductivity of at least 46 W/Km (at 0-100 deg.C) and a relatively high hardness (less than 200 HB). In a second stage, the cast iron is alloyed with 0.2-0.4% C; 0.2-0.4 Cu; 0.1-0.3 Ni; 0.1-0.2 Mo to stabilise the pearlite and raise the tensile strength. Finally, in a third stage, up to 0.1, pref. 0.06% Zr; up to 0.1, pref. 0.05 Nb/Ta; up to 0.12, pref. 0.07 Ti; and up to 0.2, pref. 0.1 V are added as nitrogen fixing agents. In the microstructure of the iron, finely divided extremely hard and high melting carbonitride crystals are precipitated. |
