PURPOSE: To carry out the recrystallization refining of a structure in the surface layer of an ingot and to manufacture a Ti product excellent in surface characteristics by previously applying working strain to the surface layer of an ingot and then applying recrystallization to the above at the time of hot- working an ingot of pure Ti or Ti alloy.
CONSTITUTION: At the time of subjecting an ingot of pure Ti or Ti alloy to hot working and cold working to manufacture the product of expanded material, such as plate stock, bar stock, wire rod, tube stock, and shape, working, such as forging and rolling, is previously applied to the ingot to apply working strain to the surface. Subsequently, heating is applied to the above up to a temp. of the recrystallization temp. of Ti or Ti alloy or above to subject the surface layer to recrystallization refining to ≥at least 2mm thickness, followed by hot working, such as hot rolling and hot extrusion. By this method, surface ruggedness due to coarse crystalline grains at the ingot surface and further the occurrence of cracks and surface flaws in stripes can be prevented and, as a result, the expanded material product of Ti or Ti alloy excellent in surface characteristics can be manufactured.
HARADA NAOAKI
KIMURA KINICHI
IRIE NOBUYASU
NISHIDA MURAAKI
YAMASHITA YOSHITO
ISHIO AKIFUMI
| JPS60230968A | 1985-11-16 | |||
| JPS61253354A | 1986-11-11 |