| 摘要 |
PURPOSE:To improve wear resistance and toughness by heating and holding a high-chromium cast iron in a specific temp. range then cooling the same thereby changing the shape itself of the eutectic carbide. CONSTITUTION:The high-chromium cast iron is heated and held to and in the temp. region higher by 80 deg.C than the solidus line from the solidus line and is then cooled. The solidus line refers to the solidification end temp. determined from a thermal analysis cooling curve when the sample at about 60 deg.C is heated and melted in gaseous Ar and is then cooled at about 20 deg.C/min rate. The holding time varies with a heat treatment temp. and is preferably about 2-10hr. The atmosphere is preferably an inert or reducing atmosphere and the cooling rate is optionally selected by the size of the material to be heat-treated and the required base structure. The aggregation and granulation of the eutectic carbide are thereby made possible and the wear resistance and toughness are improved.
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