| 摘要 |
PROBLEM TO BE SOLVED: To obtain cemented carbide in which deposition and coagulation with a material to be machined on machining can be suppressed, and a satisfactory hard film can be formed. SOLUTION: In the cemented carbide having a composition containing 2 to 10 wt.% of bonding metals of cobalt (Co) and/or nickel (Ni), and 0 to 30 wt.% of the carbide, nitride and/or carbonitride of at least one kind selected from the groups consisting of the groups 4a, 5a and 6a metals in the Periodic Table, and containing 10 to 300 ppm iron (Fe), and 100 to 1,000 ppm chromium (Cr), and the balance tungsten carbide with inevitable impurities, the vicinity of the surface is provided with a surface region satisfying the condition of psuf <pin provided that the total content of the bonding metals at the inside of the cemented carbide is defined as w1in , the total content of iron (Fe) and chromium (Cr) at the inside of the cemented carbide is defined as w2in , the total content of the bonding metals in the surface region of the cemented carbide is defined as w1suf , and the total content of iron (Fe) and chromium (Cr) in the surface region of the cemented carbide is defined as w2suf , and pin =w2in /w1in , and psuf =w2suf /w1suf .
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