Toho Titanium Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Osamu Tada

Kenichi Mori

Kazuhiro Takahashi

Hideki Fujii

Tomonori Kunieda

Hiroaki Otsuka

Hisamune Tanaka

Takashi Oda

Yoshimasa Miyazaki

Yoshihiro Fujii

Norio Yamamoto

Takeshi Shiraki

Yoshihiro Hatta

Toshihiko Sakai

Takeshi Sannohe

The present invention provides a titanium slab for hot rolling which can be fed into a general purpose hot-rolling mill for producing strip coil, without passage through a breakdown process such as blooming or a straightening process, and can further suppress surface defect occurrence of the hot-rolled strip coil, and a method of producing and a method of rolling the same, characterized in that in the cast titanium slab an angle &#x3b8; formed by the crystal growth direction (solidification direction) from the surface layer toward the interior and a direction parallel to the slab casting direction (longitudinal direction) is 45 to 90&#xb0;, and moreover, there is a surface layer structure of 10 mm or greater whose &#x3b8; is 70 to 90&#xb0;, and further characterized in that a crystal grain layer of 10 mm or greater is formed whose C-axis direction inclination of a titanium &#x3b1; phase is, as viewed from the side of the slab to be hot rolled, in the range of 35 to 90&#xb0; from the normal direction of the surface to be hot rolled. The titanium slab concerned is produced using an electron beam melting furnace by casting at an extraction rate of 1.0 cm/min or greater.

Titanium slab for hot rolling, and method of producing and method of rolling the same

The present invention provides a titanium material for hot rolling which enables reduction of defects on the surface (in the case of a flat material or strip coil, including not only the flat surfaces but also the side surfaces and edges) due to hot rolling. The titanium material for hot rolling has dimples imparted by cold plastic deformation whose mean value of the heights (Wc) of the undulation profile elements is 0.2 to 1.5 mm and mean value of the lengths (WSm) thereof is 3 to 15 mm. The invention also provides a method of producing the titanium material and a method of hot rolling the titanium material.

Titanium material for hot rolling and method of producing the same

Titanium-aluminum alloy is prepared as a master alloy, and the aluminum master alloy and a pure titanium material are melted by an electron beam to yield titanium alloy.

Process for production of titanium alloy

Growing community of inventors

Chigasaki, Japan

Osamu Tada