Shearing die and method for manufacturing the same

Abstract

The present invention provides a shearing die having longer life and a method for manufacturing the same. The invention provides a shearing die 1 comprising a pair of substrates, which is used for shearing a sheet or plate material 2 disposed therebetween by the pair of substrates, wherein a hard film formed by an arc ion plating method is provided at least on a region of a curved surface and a region from the end part of the curved surface on the side facing to the surface of the sheet or plate material 2 to 300 µm along the surface of the substrate, of the surface of at least one of the substrate, and the hard film comprises Al and one or more of Ti and Cr, and has a thickness of 1 to 5 µm, and the number of a metal particle having a diameter of 20 µm or more, which is present on a line segment having a length of 10 mm on a surface of the hard film formed on region of the curved surface and the region from the end part of the curved surface on the side facing to the surface of the sheet or plate material 2 to 300 µm along the surface of the substrate, is 2 or less.

Description

technical field [0001] The present invention relates to a shearing die for shearing plates and a manufacturing method thereof. Background technique [0002] As the strength of metal materials such as high-strength steel materials (high tension steel materials) increases, shortening of the life of shear dies used for shear processing of plate materials containing the metal materials has become a problem. Therefore, in order to solve this problem, techniques for forming various hard coatings on the base material of the mold as shown below have been developed. [0003] For example, Patent Document 1 discloses a technique of forming any one of Group IV carbides, nitrides, and carbonitrides on the surface of a base material of a shearing flat blade. In addition, Patent Document 2 discloses a technique in which a titanium nitride ceramic is formed as an inner layer, a titanium metal layer is formed as an intermediate layer, and a titanium nitride layer is formed as an outer layer...

AI Technical Summary

Problems solved by technology

[0009] However, the techniques disclosed in Patent Documents 1 to 3 use Group IV carbides, nitrides, or carbonitrides as hard coatings, so the hardness of the mold is about 2500 HV (Vickers hardness), which is not sufficient hardness.

Therefore, the techniques disclosed in Patent Documents 1 to 3 still have problems in terms of life extension.

[0010] In addition, the technique disclosed in Patent Document 3 uses ion nitriding to harden the base material to form a hard film. However, the base material itself is hardened, which makes the entire mold brittle and accelerates the accelerated cracking of the mold.

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