PURPOSE: To improve subsequent plastic workability by subjecting the part to be worked to the working of giving strain prior to plastic working of a titanium or zirconium material.
CONSTITUTION: Prior to plastic working of a titanium or ziroconium material, at least the part to be plastically worked is subjected to the working of giving strain at about -196°CWordinary temperature lower than plastic working temperatures. Since twins are produced in the strained part and deformation limit is increased, the subsequent plastic working improves. It is desirable to perform the plastic working after the straining at relatively low temperatures of 100W400°C in order to decrease the deformation resistance of the material and to suppress for formation of scale on the surfaces.
KOIKE MASAO
ISHIYAMA SHIGEJI
NIPPON STAINLESS STEEL CO