| 摘要 |
775,400. Making cased tubes; drawing. BENTELER - WERKE AKT. - GES. WERK NEUHAUS. May 19, 1955 [May 19, 1954; April 9, 1955], No. 14498/55. Drawings to Specification. Classes 83 (2) and 83 (4). [Also in Group XXXVI] In a method of making small diameter steel tubes provided with internal and external coatings of copper or copper alloys, a large diameter steel tube has electrodeposited layers of copper applied while held in the vertical position with a copper wire anode running through the centre, the tube and anode being connected at both ends to sources of electric current and electrolyte being passed continuously through the tube. The plated tube is finally annealed in the absence of oxygen at a temperature just below the melting-point of copper and the tube is cold drawn to the required dimensions. |
