Y. Itsumi, H. Ooyama, KOBE STEEL.LTD, Takasago, Japan; K. Tada, KOBE STEEL.LTD, Kakogawa, Japan; T. Kudo, KOBE STEEL.LTD, Kobe, Japan; T. Konno, KOBE STEEL, Ltd, Takasago, Japan
KS Ti-9 has been developed as substitute for Ti-6Al-4V alloy, which has been widely used in aerospace parts.
However, this alloy shows strong in-plane anisotropy in strength and bendability when manufactured by the
conventional method, that is, by a uni-directional rolling process in the α-β region. In order to reduce inplane
anisotropy, we have adopted the β rolling process, defined as the process of rolling after heating the
slub in the β region. This new process results in forming a weaker transverse-texture than that obtained by
the conventional method, as it offers a much better chance for new α nucleation with random crystal
orientation in cooling from β into the α-β phase. Trial sheet manufactured by the new process on a mass
production line also exhibits less in-plane anisotropy and has the same properties as Ti-6Al-4V.