| 摘要 |
PURPOSE:To prevent damage on wiredrawn surface, to improve efficiency by improving the rate of wire drawing per operation and to make improvement in the shape of products, by previously carrying out continuous warm wire drawing at a prescribed temp. in an open air atmosphere in subjecting an NiTi alloy to cold wire drawing with allowing an oxide film to remain on it. CONSTITUTION:The NiTi alloy consisting of 49-52at% Ni and the balance Ti or the NiTi alloy containing, as a part of the above Ni or Ti, <=4at%, in total, or >=1 kind among Fe, Cr, Mn, Co, Cu, Al, etc., is subjected to wire drawing. For example, a wire rod 1 with about 2mm diameter made by subjecting the surface of said NiTi alloy to bright treatment by pickling is first prepared, which is passed through a high-speed heating electric furnace 2 with the open air atmosphere held at a prescribed temp. and, directly after heating to 300-700 deg.C, the wire rod 1 is subjected to warm wire drawing through a wire drawing die 3. The wire rod 1 is held again at 300-700 deg.C in a furnace 2' and is then subjected to warm wire drawing through a die 4 and cooled, which is fed to dies 5-7 to be subjected to cold wire drawing, followed by rolling round a reel 8.
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