| 摘要 |
1,256,772. Making tubes; skelping; welding by pressure. VALLOUREC (USINES A TUBES DE LORRAINE-ESCAUT ET VALLOUREC REUNIES) ELPHIAC S.A. 14 Aug., 1969 [16 Aug., 1968], No. 40636/69. Headings B3A, B3E and B3R. In a method and apparatus for producing a welded tube from metal strip the strip is preheated in a furnace, formed into a tube with the edges of the strip adjacent each other with a small gap between them, the edges are superheated, preferably by electric induction heating, a gas is blown on to the edges and the tube welded by bringing the edges together by means of forming rollers. The gas may be oxygen, air or a mixture thereof, or steam. The heating in the furnace is preferably to 900‹ to 1300‹ C. with superheating of from 50‹ to 450‹ C. in the case of steel strip. |
