| 摘要 |
PROBLEM TO BE SOLVED: To further improve the wear resistance of a cast iron component compared with a conventional wear resistant one by heightening its hardness. SOLUTION: The raw material of a cast iron comprising, by weight, 2.0-3.5% C, 0-1.0% Si, 0.5-1.5% Mn, 0-1.5% Ni, 18.0-23.0% Cr, 1.0-3.0% Mo and the balance Fe with inevitable impurities is melted. When tapping the molten metal, a free N is fixed by adding Ti into a ladle, and then a cast iron component is cast from the obtained molten metal. After the cooled cast iron component is taken out of a mold, it is heated to a temperature of 1,030-1,070 deg.C. The component is kept at such a temperature over 1 hr per 1 inch of its thickness, and then is subjected to a normalizing treatment by air cooling. Thereafter, the component is heated to a temperature of 490-510 deg.C, is kept at the temperature over 1 hr per 1 inch of its thickness, and finally is subjected to a tempering treatment by furnace cooling.
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