Hardness evaluation method of cold working components and generation method of equivalent plastic deformation hardness curve

摘要

The present invention provides a method for estimating the hardness of a cold worked part, wherein: a placement platform on which a test piece is placed, and a punch of which a contacting surface which comes into contact with the test piece is a curved surface are used to compress the test piece, placed on the placement platform, to create a test piece for hardness measurement having a recessed portion with a shape corresponding to the shape of the contacting surface of the punch; the hardness of the test piece for hardness measurement is measured at a plurality of hardness measuring positions in a measuring direction, where the direction in which the plate thickness changes in the recessed portion is taken as the measuring direction; an equivalent plastic strain is calculated by numerical analysis; a hardness/equivalent plastic strain curve is acquired on the basis of the hardness and the equivalent plastic strain at each hardness measuring position; a value of the equivalent plastic strain of the cold worked part is calculated by numerical analysis; and the hardness is identified on the basis of the hardness/equivalent plastic strain curve, from the calculated value of the equivalent plastic strain at an arbitrarily defined location in the cold worked part.