| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing method by which high dimensional accuracy equal to a cold drawn product is obtained by slight diameter reducing rolling so as to suppress the deterioration of workability as far as possible. <P>SOLUTION: By using total one stand of a four-roll type sizing roll stand on which rolls 1 for sizing rolling are arranged one pair by one pair up and down, and right and left, or using n stands which are total two or more of a similar four-roll type sizing roll stand are made in series, by using the four-roll type sizing roll stand of total n stands in which roll phase difference between two adjacent stands is taken as an angle divided into n equal parts of 90°, the diameter reducing rolling of 0.5-3% in the total diameter reducing rate is applied to a pipe 10 to be rolled. <P>COPYRIGHT: (C)2013,JPO&INPIT |
