| 摘要 |
PCT No. PCT/NO85/00082 Sec. 371 Date Aug. 14, 1986 Sec. 102(e) Date Aug. 14, 1986 PCT Filed Dec. 27, 1985 PCT Pub. No. WO86/04005 PCT Pub. Date Jul. 17, 1986.In a method for heating metal elements (1,2) which are to be joined, for example by forge welding, there is used a high frequency resistance heating. The elements are provided with surfaces to be welded and are positioned so that said surfaces constituted a narrow gap (3). The current is conducted from a high frequency current source (11) through a contact (9) into one of the elements (1), wherefrom the current follows the material close to the gap surface (4) and to the opposite side of the element, where the current flows via further contacts (8,9) and a conductor (10) to the other element (2). From here the current follows the other gap surface (5) to another contact (7) and the current source (11). The current will follow a path close to the gap surfaces since these surfaces will give the path of smallest total impedance, the current thereby establishing a narrow and efficient heating zone in the vicinity of said gap surfaces. |
