| 摘要 |
The present invention relates to a coated cemented carbide insert with a binder phase enriched surface zone. The WC-grains have an average grain size in the range 1.0-3.5 mum, preferably 1.3-3.0 mum and the number of WC-grains larger than 2 times the average grain size is less than 10 grains/cm2 measured on a representative polished section 0.5 cm2 large, preferably less than 5 grains/cm2, and the number larger than 3 times the average grain size is less than 5 grains/cm2, preferably less than 3 grains/cm2. The cemented carbide is made by powder metallurgical methods and is in particular characterized in that the cooling rate, CR, from the sintering temperature, ST, exhibits the relationship 10<CR.(ST-1300)/1000<17.
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