Method of plastic working of metal materials
 Method of thermal plastic working of metal materials whereby a material is heated or cooled with measurements being made of variations in the metallographical condition of the material which may occur as the temperature of the material is varied due to the foregoing treatment. If the measurement shows that the material has effected a sudden change in its metallographical condition, the temperature having caused such a sudden change or higher temperature may be used to perform a desired plastic working of the material in its most plastic-workable condition. 
Daido Tokushuko Kabushiki Kaisha
B B B C C
B21C B21J B21J C21D C21D
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Makoto Masashi Hiroyasu Katuhiro Shigeki
Saito Mizuno Nagasaka Kozima Sawa