| 摘要 |
PURPOSE:To prevent an accident, such as the breaking of a W wire during wire drawing, to minimize variation in wire diameter, and to prolong the life of a wire drawing die, by heating the W wire in oxidative atmosphere after removing surface oxides simultaneously with heating and annealing in reducing atmosphere and thus forming a prescribed wt% oxide coating on the surface, and then drawing the wire. CONSTITUTION:Before a W wire is introduced into a die, the wire is heated at 1,400-1,700 deg.C in reducing atmosphere normally of hydrogen and annealed while oxides on the surface of the W wire are removed. The resulting W wire is heated in oxidative atmosphere wherein O2 concentration, heating temperature, etc., are adjusted properly to form a 1.0-1.5wt% oxide coating on the surface of the W wire basing on its weight. The W wire having this oxide coating is coated with a lubricant and then introduced into said die to be drawn into a thin wire. |
