PURPOSE: To obtain a titled hot-rolled Ti alloy sheet which can be easily reduced in thickness, by forming a blank material for a hot-rolled α+β type alloy sheet into the three-layered structure wherein both surfaces of said material are coated with metallic sheets having specified material quality and thickness, heating the blank material in a prescribed temp. region and subjecting the heated material to hot rolling in succession.
CONSTITUTION: Both surfaces of a blank material for a hot-rolled α+β type Ti alloy such as Ti-6Al-4V alloy (β transformation point; 970W1,000°C) are coated with any of pure Ti sheet, mild steel sheet and ferritic stainles steel sheet of ≥3mm thickness whereby the blank material is made into the three-layered structure. The m. p. of these coating materials is appreciably higher than the heating temp. for hot rolling. The blank material for the hot rolled α+β type Ti alloy sheet made into such three-layered structure is heated to a 80°CWβ transformation point temp. region, and is then subjected to hot rolling. The end temp. in the hot rolling is determined at ≥570°C, whereby the intended hot-rolled α+β type Ti alloy sheet having excellent suitability to cold rolling is obtd.
NOKOYA MASAKI
SHIICHI MASARU
ISHIYAMA SHIGEJI
TAKAHASHI YUKIHISA
FUJISAWA KAZUYOSHI
