| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a steel bar or a wire rod by which the generation of surface flaws is prevented when manufacturing the steel bar or the wire rod by performing the tandem rolling of a square steel product having an approximately regular square cross-sectional shape and also line flaws are not generated on the surface even when forging the obtained steel bar or the wire rod. SOLUTION: When manufacturing the steel bar or the wire rod by rough rolling the square steel product having an approximately regular square in the cross-sectional shape with a tandem mill in which stands the rolling directions of which are crossed orthogonally each other are alternately lined up and, after that, further by continuing rolling, before rough rolling, the distances between two pairs of opposite sides are respectively measured about the cross section of the above square steel product and, when the difference between their distances excess a predetermined value, it is better to perform the tandem rolling after grinding the surface of the square steel product so as to be less than the predetermined value. COPYRIGHT: (C)2009,JPO&INPIT
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