| 摘要 |
913,063. Making tubes; bending; rolling; welding. BENTELER-WERKE A.G. June 12, 1959 [June 13, 1958], No. 20152/59. Classes 83 (2) and 83 (4). In a method of continuously producing small-section, e.g. 20-3 mm. diameter welded steel tubes a strip is drawn through a plurality of freely-rotating undriven bending roll sets 6a, 6b, 6c to form a slotted tube, the slot in the tube is welded to form a longitudinal seam and the tube is then passed through guide rolls 16a 16b, 16c, 16d to prevent twist and to slightly deform the tube prior to cold-reduction in a mill which supplies the traction for the previous operations, the reducing mill comprising pairs of rolls 3a, 3b, 3c with oval-shaped passes arranged alternately at relative angles of 90 degrees and a final pair of rolls 3d with a circularshaped pass, the relative speeds of the roll pairs in the reduction mill being such that the material of the tube is stressed beyond its yield point. A steel suitable for deep-drawing is fed from a reel 2, by the traction of the reduction mill, through an edge-trimming cutter 5 prior to skelping. Adjustable closing rolls 7 are provided in advance of the welding point together with a sword 10 (Fig. 3, not shown), for correct alignment of the slot for welding. Pressure rolls 8 are provided at the welding point and welding is effected either by the argon arc process using a tungsten electrode 12 or by a resistance butt-welding process. In the latter case a bead-removing tool may be fitted to the bracket 9 carrying the sword 10. The guide rolls 16a, 16b, 16c have passes with alternately circular and oval grooves. Various diameters of finished tube may be produced from a skelp of the same width merely by removing an appropriate number of intermediate stands from the reducing mill. A traversable saw 18 cuts up the tube issuing from the mill. |
