Production methods for Ti—Al alloys may include: adding a flux including calcium oxide containing 35+wt. % calcium fluoride, to a melt starting material of Ti material and Al material and with 50+wt. % Al; introducing the fluxed melt starting material into a water-cooled copper crucible having a tapping port in the bottom, induction melting it inside the water-cooled copper crucible in at least a 1.33 Pa atmosphere; the flux, containing oxygen released from the melt starting material by the induction melting, is separated out by tapping the melt starting material, which was induction melted in the water-cooled copper crucible, downward from the tapping port; and when obtaining the Ti—Al alloy by casting the flux-removed melt starting material, the induction melting output is reduced to no more than 90% of that during melting and tapping is performed from the water-cooled crucible with the output in a reduced state.

A blade has an attachment root and an airfoil, the airfoil having a proximal end and a distal end. The blade has a compositional variation along the airfoil.

A blade has an attachment root and an airfoil, the airfoil having a proximal end and a distal end. The blade has a compositional variation along the airfoil.

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 α 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 α 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 α 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%.

A method for producing a metal ingot by using an electron-beam melting furnace having an electron gun and a hearth that accumulates a molten metal of a metal raw material, wherein the metal raw material is supplied to the position on a supply line disposed along a second side wall of the hearth that accumulates the molten metal of the metal raw material. A first electron beam is radiated along a first irradiation line that is disposed along the supply line and is closer to a central part of the hearth relative to the supply line on the surface of the molten metal, wherein a surface temperature (T2) of the molten metal at the first irradiation line is made higher than an average surface temperature (T0) of the entire surface of the molten metal in the hearth.

A method for producing a metal ingot by using an electron-beam melting furnace having an electron gun and a hearth that accumulates a molten metal of a metal raw material, wherein the metal raw material is supplied to the position on a supply line disposed along a second side wall of the hearth that accumulates the molten metal of the metal raw material. A first electron beam is radiated along a first irradiation line that is disposed along the supply line and is closer to a central part of the hearth relative to the supply line on the surface of the molten metal, wherein a surface temperature (T2) of the molten metal at the first irradiation line is made higher than an average surface temperature (T0) of the entire surface of the molten metal in the hearth.

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.

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 β stabilizer elements to the surface and melting and resolidifying the surface. An average value of β stabilizer element concentration in a range of within 1 mm in depth is higher than β 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 β 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.

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 β stabilizer elements to the surface and melting and resolidifying the surface. An average value of β stabilizer element concentration in a range of within 1 mm in depth is higher than β 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 β 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.

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 α 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 α 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 α 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%.