摘要 |
Improved gray iron compositions comprise at least about 90 weight % iron, at least about 3.40 weight % carbon, from about 1 to 2.5 weight % silicon, from about 0.4 to 1.0 weight % manganese, and from about 0.02 to 0.07 weight % tin. Preferably, the gray iron compositions of the invention also include from about 0.2 to about 0.5 weight % chromium, and may further preferably include from about 0.25 to 0.75% molybdenum and/or from about 0.3 to 1.0% copper, and may optionally also include small amounts (less than about 1%) of such elements as titanium or vanadium, as examples. The gray iron compositions which may advantageously be used in the manufacture of vehicle brake components, especially the braking surfaces of vehicle brake drums or brake rotors. |