| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a steel tube stably satisfying a target value of a mechanical property.SOLUTION: When a steel tube is manufactured by applying cold forming to a steel sheet, a method for manufacturing the steel tube includes: calculating a predicted value &Dgr;&sgr;of a mechanical property variation of a steel material caused by tube forming; obtaining a predictable accuracy setting value S; and selecting a combination of a steel sheet, a method for manufacturing the same, and tube forming conditions, so as to satisfy the following formula (i): &sgr;-&Dgr;&sgr;+S≤&sgr;≤&sgr;-&Dgr;&sgr;-S, and, thereby forming the steel tube. Here, in the formula (i), &sgr;is an upper limit of a target value of a mechanical property after tube forming, &sgr;is a lower limit of the target value of the mechanical property after tube forming, and &sgr;is the mechanical property of the steel sheet. |
