| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a titanium alloy billet having excellent defect detectability in an ultrasonic crack inspection test, even in a large-sized billet with a diameter of ≥ϕ150 mm, for which the inspection of internal defects can be performed by a generally used ultrasonic crack inspection method similarly to the case of the other metal products, and which can be mass-produced as well. Ž<P>SOLUTION: Regarding the titanium alloy billet having the diameter of ≥ϕ150 mm and an almost columnar shape and prescribed by AMS4928, in a region where the total area of the optional-cross section parallel to the axial direction of the central part is ≥400,000 μm<SP>2</SP>, the area ratio of the primary α phase with an aspect ratio of ≤2.0 occupied in the whole structure is ≥10%. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
