Abstract: This titanium alloy sheet contains predetermined chemical components, an area ratio of an ?-phase is 80% or more, an area ratio of the ?-phase having an equivalent circle diameter of 1 ?m or more is more than 53%, and in a (0001) pole figure in a sheet thickness direction, an angle formed between the sheet thickness direction and a direction indicating a peak of intensity calculated by texture analysis in a case in which a series rank is 16 and the Gaussian half width is 5° for an inverse pole figure using a spherical harmonics method of an electron backscatter diffraction method is 65° or less, and the average sheet thickness is 2.5 mm or less.

Abstract: A titanium alloy thin sheet contains specific chemical components, in which, when a crystal orientation of an ?-phase is expressed by an Euler angle g={?1, ?, ?2} according to Bunge's notation method, the orientation with maximum intensity expressed by a crystal orientation distribution function f(g) calculated with Series Rank of 16 and a Gaussian half width of 5° in texture analysis using a spherical harmonics method of an electron backscatter diffraction method is in the range of ?1: 0 to 30°, ?: 60 to 90°, and ?2: 0 to 60°, and a degree of accumulation of the orientation with maximum intensity is 10.0 or more, a 0.2% proof stress in a sheet width direction at 25° C. is 800 MPa or more, a Young's modulus in the sheet width direction is 125 GPa or more, and an average sheet thickness is 2.5 mm or less.

Abstract: A titanium alloy member by mass %, Al: 4.0% to 9.0%, one or more selected from the group consisting of Fe, Cr, and Ni: 0.5% to 2.5% in total, C: 0% to 0.100%, N: 0% to 0.100%, H: 0% to 0.100%, O: 0% to 0.500%, and a remainder including Ti and impurities, in which the titanium alloy member includes a hard part having a Vickers hardness of 350 HV or greater.

Abstract: Provided is a titanium cast product for hot rolling made of commercially pure titanium, the titanium cast product including a melted and resolidified layer in a range of more than or equal to 1 mm in depth on a surface serving as a rolling surface, the melted and resolidified layer being obtained by adding one or more elements out of any one of or both of at least one ? stabilizer element and at least one neutral element to the surface, and melting and resolidifying the surface. An average value of a total concentration of the at least one ? stabilizer element and the at least one neutral element in the range of more than or equal to 1 mm in depth is higher than a total concentration of the at least one ? stabilizer element and the at least one neutral element in a base metal by, in mass %, more than or equal to 0.1% and less than 2.0%.

Abstract: A method for producing a hot-rolled titanium plate includes, [1] melting at least one part of the side surface of the titanium slab by radiating a beam or plasma toward the side surface, not toward the surface to be rolled, and thereafter causing re-solidification to form, in the side surface, a layer having grain diameter of 1.5 mm or less and a depth of 3.0 mm or more from the side surface; [2] performing a finishing process on the surface to be rolled of the titanium slab in which the layer is formed, to thereby bring a slab flatness index X to 3.0 or less; and [3] subjecting the titanium slab after the finishing process to hot rolling under a condition in which a length of an arc of contact of a roll L in a first pass of rough rolling is 230 mm or more.

Abstract: A titanium alloy material contains: in mass %, Cu: 0.7% to 1.4%; Sn: 0.5% to 1.5%; Si: 0.10% to 0.45%; Nb: 0.05% to 0.50%; Fe: 0.00% to 0.08%; O: 0.00% to 0.08%; and the balance composed of Ti and impurities, in which in a structure, an area fraction of an ? phase is 96.0% or more and an area fraction of an intermetallic compound is 1.0% or more, and an average crystal grain size of the ? phase is 10 ?m or more and 100 ?m or less and an average grain size of the intermetallic compound is 0.1 to 3.0 ?m.

Abstract: A bar includes a titanium alloy containing an ? phase and a ? phase, in which the titanium alloy contains, as a chemical composition, by mass %: Al: 4.5% to 6.4%; Fe: 0.5% to 2.1%; C: 0.01% or less; N: 0.05% or less; O: 0.25% or less; V: 0.10% or less; Si: 0% to 0.40%; Ni: 0% to 0.15%; Cr: 0% to 0.25%; Mn: 0% to 0.25%; and a remainder including Ti and impurities, an area ratio of the ? phase in a metallographic structure of the titanium alloy is 20% or less, and an average minor axis length of grains of the ? phase is 2.0 ?m or less.

Abstract: An ?+? type titanium alloy wire contains, in mass %, Al: 4.50 to 6.75%, Si: 0 to 0.50%, C: 0.080% or less, N: 0.050% or less, H: 0.016% or less, O: 0.25% or less, Mo: 0 to 5.5%, V: 0 to 4.50%, Nb: 0 to 3.0%, Fe: 0 to 2.10%, Cr: 0 to less than 0.25%, Ni: 0 to less than 0.15%, Mn: 0 to less than 0.25%, and the balance being Ti and impurities, the contents of Al, Mo, V, Nb, Fe, Cr, Ni, and Mn satisfying an equation, in which an average aspect ratio of an ? crystal grain is 1.0 to 3.0, a maximum crystal grain diameter of the ? crystal grain is 30.0 ?m or less, an average crystal grain diameter of the ? crystal grain is 1.0 to 15.0 ?m.

Abstract: A titanium composite material 1 is provided that includes: an inner layer 5 consisting of a commercially pure titanium or a titanium alloy; an outer layer 3 formed on at least one surface of the inner layer 5 and having a chemical composition that is different from a chemical composition of the inner layer 5; and an intermediate layer formed between the inner layer 5 and the outer layer 3 and having a chemical composition that is different from the chemical composition of the inner layer 5. The thickness of the outer layer 3 is 2 ?m or more, and occupies no more than 40% of the overall thickness per side. The thickness of the intermediate layer is 0.5 ?m or more. Despite being inexpensive, this titanium composite material has desired characteristics.

Abstract: A titanium material for hot rolling 1 includes a titanium cast piece 3, and titanium sheets 4 that are welded to faces corresponding to rolling surfaces 3a of the titanium cast piece 3. The titanium cast piece 3 and the titanium sheets 4 have the same kind of chemical composition. The titanium material for hot rolling 1 can maintain good surface properties after hot rolling even if a slabbing process or a finishing process is omitted.

Abstract: A titanium alloy material contains: in mass %, Cu: 0.7% to 1.4%; Sn: 0.5% to 1.5%; Si: 0.10% to 0.45%; Nb: 0.05% to 0.50%; Fe: 0.00% to 0.08%; O: 0.00% to 0.08%; and the balance composed of Ti and impurities, in which in a structure, an area fraction of an ? phase is 96.0% or more and an area fraction of an intermetallic compound is 1.0% or more, and an average crystal grain size of the ? phase is 10 ?m or more and 100 ?m or less and an average grain size of the intermetallic compound is 0.1 to 3.0 ?m.

Abstract: A method for producing a hot-rolled titanium plate includes, [1] melting at least one part of the side surface of the titanium slab by radiating a beam or plasma toward the side surface, not toward the surface to be rolled, and thereafter causing re-solidification to form, in the side surface, a layer having grain diameter of 1.5 mm or less and a depth of 3.0 mm or more from the side surface; [2] performing a finishing process on the surface to be rolled of the titanium slab in which the layer is formed, to thereby bring a slab flatness index X to 3.0 or less; and [3] subjecting the titanium slab after the finishing process to hot rolling under a condition in which a length of an arc of contact of a roll L in a first pass of rough rolling is 230 mm or more.

Abstract: Provided is a titanium cast product for hot rolling made of commercial pure titanium or a titanium alloy, the titanium cast product including, in a surface serving as a rolling surface, a fine structure layer that is formed of an acicular structure formed in the outermost surface by melting and re-solidification treatment and that has a thickness of more than or equal to 5 mm and less than 9 mm in depth. In the titanium cast product for hot rolling according to the present invention, the surface is flat, the number of minute voids in the interior immediately below the surface is small, and the outermost surface has a significantly fine structure. When the titanium cast product is subjected to hot rolling, the occurrence of concavities on the surface in the early stage of hot rolling and the occurrence of surface defects on the hot rolled sheet can be stably prevented at a practical level.

Abstract: Provided is a titanium cast product made of commercially pure titanium, the titanium cast product being produced by electron-beam remelting or plasma arc melting, comprising: a melted and resolidified layer in a range of 1 mm or more in depth at a surface serving as a surface to be rolled, the melted and resolidified layer being obtained by adding one or more kinds of ?stabilizer elements to the surface and melting and resolidifying the surface. An average value of ? stabilizer element(s) concentration in a range of within 1 mm in depth is higher than ?stabilizer element(s) concentration in a base material by, in mass %, equal to or more than 0.08 mass % and equal to or less than 1.50 mass %. As the material containing the ? stabilizer element, powder, a chip, wire, or foil is used. As means for melting a surface layer, electron-beam heating and plasma arc heating are used.

Abstract: A titanium slab for hot rolling comprised of a titanium slab obtain by smelting commercially pure titanium, wherein even if the breakdown process is omitted, the strip shaped coil after hot rolling is excellent in surface properties and a method of smelting that titanium slab are provided. The titanium slab according to the present invention is a titanium slab for hot rolling obtained by smelting commercially pure titanium including the ? phase stabilizing element Fe, wherein the formation of coarse ? phases is suppressed by making the average Fe concentration down to 10 mm from the surface layer of the surface which corresponds to at least the rolling surface of the titanium slab 0.01 mass % or less. A titanium slab obtained by smelting commercially pure titanium can be obtained by cooling until the surface becomes the ? transformation point or less, then reheating it to the ? transformation point or more, and gradually cooling from the slab surface layer.

Abstract: There is provided a titanium cast product for hot rolling composed of commercially pure titanium, the titanium cast product including: a microstructural refinement layer having acicular microstructure on an outermost layer of a surface layer to be rolled; and an inside microstructural refinement layer having acicular microstructure provided in an inside of the microstructural refinement layer. Cast solidification microstructure is present more inward than the inside microstructural refinement layer. The microstructural refinement layer has finer microstructure than the inside microstructural refinement layer. The microstructural refinement layer is present in a range of a depth of 1 mm or more and less than 6 mm from the surface. The inside microstructural refinement layer is present in an inside of the microstructural refinement layer in a range of a depth of 3 mm or more and 20 mm or less from the surface.

Abstract: A titanium composite material 1 is provided that includes: an inner layer 5 consisting of a commercially pure titanium or a titanium alloy; an outer layer 3 formed on at least one surface of the inner layer 5 and having a chemical composition that is different from a chemical composition of the inner layer 5; and an intermediate layer formed between the inner layer 5 and the outer layer 3 and having a chemical composition that is different from the chemical composition of the inner layer 5. The thickness of the outer layer 3 is 2 ?m or more, and occupies no more than 40% of the overall thickness per side. The thickness of the intermediate layer is 0.5 ?m or more. Despite being inexpensive, this titanium composite material has desired characteristics.

Abstract: A titanium material for hot rolling 1 includes a titanium cast piece 3, and titanium sheets 4 that are welded to faces corresponding to rolling surfaces 3a of the titanium cast piece 3. The titanium cast piece 3 and the titanium sheets 4 have the same kind of chemical composition. The titanium material for hot rolling 1 can maintain good surface properties after hot rolling even if a slabbing process or a finishing process is omitted.

Abstract: Provided is a titanium cast product for hot rolling made of a titanium alloy, the titanium cast product including a melted and resolidified layer in a range of more than or equal to 1 mm in depth on a surface serving as a rolling surface, the melted and resolidified layer being obtained by adding one or more elements out of any one of or both of at least one ? stabilizer element and at least one neutral element to the surface, and melting and resolidifying the surface. An average value of a total concentration of at least one ? stabilizer element and at least one neutral element in the range of more than or equal to 1 mm in depth is higher than a total concentration of at least one ? stabilizer element and at least one neutral element in a base metal by, in mass %, more than or equal to 0.1% and less than 2.0%.

Abstract: Provided is a titanium casting product made of titanium alloy, the titanium casting product being produced by electron-beam remelting or plasma arc remelting, comprising: a melted and resolidified layer in a range of 1 mm or more in depth at a surface serving as a surface to be rolled, the melted and resolidified layer being obtained by adding one or more kinds of ? stabilizer elements to the surface and melting and resolidifying the surface. An average value of ? stabilizer element concentration in a range of within 1 mm in depth is higher than ? stabilizer element concentration in a base material by, in mass %, equal to or more than 0.08 mass % and equal to or less than 1.50 mass %. As the material containing the ? stabilizer element, powder, a chip, wire, or foil is used. As means for melting a surface layer, electron-beam heating and plasma arc heating are used.