| 摘要 |
Steel or iron alloy sheet metal, particularly low C non-killed steels for car-body panels, having a lower critical temp. over 320 degrees C and being such that dissolved atoms (N or C) interact with displacements in alloy under formation of an upper elastic limit, are heated quickly to a temp. from 320 degrees C up to the lower critical temp. of alloy, whereby dissolved atoms are split off from displacements, and alloys is then quickly cooled at speed sufficient to prevent re-combining of dissolved atoms with the displacements, whereby the upper elastic limit is temporarily removed. Treatment prevents fissure-formation in cold-working, without loss in ductility or strength. Cooling pref. takes place by quenching in liquid, such as water. Pref. alloy is heated by exposure to electromagnetic radiation with 1-500 kHz frequency.
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