Patent ID: 7740719

Claim:
A cutter comprising a Ni—Cr alloy comprising: from 32 to 44 mass percent of Cr, from 2.3 to 6 mass percent of Al, the balance being Ni, impurities, and additional trace elements, and wherein the cutter has a Rockwell C hardness of 52 or more, and wherein the Ni—Cr alloy further comprises: from 0.005 to 0.025 mass percent of Mg; from 0.005 to 0.02 mass percent of Ca; from 0.005 to 0.03 mass percent of B; and from 0.005 to 0.02 mass percent of rare earth elements including Y; as the impurities and the additional trace elements, and wherein the total content of Mg, Ca, and B is greater than 0.015 and less than or equal to 0.03 mass percent, the total content of P, O, and S is greater than zero and less than or equal to 0.003 mass percent and the total content of Mn, Cu and Si is greater than zero and less than or equal to 0.03 mass percent, wherein the Ni—Cr alloy comprises a texture comprising a mixture of a Cr-rich α phase, a Ni-rich phase γ phase, and an intermetallic compound phase composed of Ni 3 Al as a basic composition γ phase and the Ni—Cr alloy has an average grain size of 1 mm or less, wherein the cutter comprises a mirror-finished surface formed by final polishing with a polisher, so that the cutter has an aesthetic property, and wherein a moving distance of the cutter required for completely cutting a hemp rope is doubled or less compared with an initial state of the cutter even after 1,000 cut operations are performed when a rope cut test is performed under conditions that a linear blade part of the cutter is pressed on a hemp rope having a diameter of 10 mm and the cutter is reciprocated in the horizontal direction while a load of 2 kg is applied to the cutter whereby the moving distance of the cutter required for completely cutting the hemp rope is repeatedly measured.