Cutting tool
AssigneeNachi-Fujikoshi Corp.
InventorsHirokuni Amano, Yuji Shimatani, Kiyoshi Nakagawa, Syunichi Asakura
Life of this patent
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Abstract
A cutting tool having cutting edges made of a high speed tool steel exhibiting very high wear and anti-chipping resistances, and sufficient toughness is provided. The high speed tool steel consists essentially of by weight C:0.6 to 1.8%, Si:1.2% max, Mn:0.5% max, Cr:3.5 to 5.0%, Mo:10% max, W:21% max, V:2 to 4% and Co:7 to 10%, the balance being Fe and incidental impurities, and the steel of the cutting edge comprise MC-type carbide grains each having a maximum equal value diameter of a circle ranging substantially 5 to 14 μm, and the MC-type carbide grains having an equal value diameter of the circle ranging substantially 5 to 14 μm have a ratio between short and long diameters ranging over substantially 0.3.
Claims10
A cutting tool having a cutting edge made of a high speed tool steel consisting essentially of by weight C:0.6 to 1.8%, Si:1.2% max, Mn:0.5% max, Cr:3.5 to 5.0%, Mo:10% max, W:21% max, V:2 to 4% and Co:7 to 10%, the balance being Fe and incidental impurities, and the steel of the cutting edge comprising MC carbide grains each having a maximum equal value diameter of a circle ranging substantially 5 to 14 μm, which equal value diameter of the circle being a diameter of any one of a circle being converted to the circle having the same cross sectional area as that of a cross sectional area of any one of the MC carbide grains, and the MC carbide grains having an equal value diameter of a circle ranging substantially 5 to 14 μm have a ratio between short and long diameters ranging over substantially 0.3, wherein the ratio between short and long diameters is a value obtained by dividing a short diameter of any one of the MC carbide grains by a long diameter of the same.
A cutting tool having a cutting edge made of a high speed tool steel consisting essentially of by weight C:0.6 to 1.8%, Si:1.2% max, Mn:0.5% max, Cr:3.5 to 5.0%, Mo:10% max, W:21% max, V:4 to 6% and Co:4 to 9%, the balance being Fe and incidental impurities, and the steel of the cutting edge comprising MC carbide grains each having a maximum equal value diameter of a circle ranging substantially 5 to 14 μm, which equal value diameter of the circle being a diameter of any one of a circle being converted to the circle having the same cross sectional area as that of a cross sectional area of any one of the MC carbide grains, and the MC carbide grains having an equal value diameter of a circle ranging substantially 5 to 14 μm have a ratio between short and long diameters ranging over substantially 0.3, wherein the ratio between short and long diameters is a value obtained by dividing a short diameter of any one of the MC carbide grains by a long diameter of the same.
Dependencies are inferred from the claim text.