| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and equipment for expanding and processing tubes, by which productivity is improved than that of a conventional method and equipment and further energy which is needed for normalizing is less than that of the conventional method and equipment. <P>SOLUTION: In the method for expanding and processing the steel tube, the steel tube is expanded and processed with a tapered part, by inserting the steel tube from the side of the base end of a mandrel provided with, on a tip thereof, a plug having the tapered part, in which the diameter is gradually increased toward the side of the tip. In the method for expanding and processing the steel tube, a normalizing treatment is applied, by heating the steel tube when being passing through the tapered part with a heating device which is arranged on the outside of the steel tube, and by heating and holding the steel tube immediately after expanding and processing the steel tube with a heating/holding device which is arranged on the outside of the steel tube. <P>COPYRIGHT: (C)2012,JPO&INPIT |
