| 摘要 |
PURPOSE:To improve a shape and dimensional accuracy and to simplify a process by the abbreviation of a heating stage by fitting a material to be straightened into upper and lower split dies engraving the closed shape of a dissimilar sectional form stock and heating it with pressurizing. CONSTITUTION:A rough straightening material 5 is pinched by the upper and lower dies 7, 8 composing a closed hole 6. The hold 6 is preferrably subjected to a solid chrome plating to improve the dulability of the dies. It is inserted with the dies into a specified heat treatment furnace in the state of pinching the material 5 to be straightened and held by heating to an annealing temp. With this method the dimensional accuracy is improved and the process can be abbreviated.
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