Kobe Steel, Ltd.

Daisuke Matsuwaka

Hitoshi Ishida

Daiki Takahashi

Hideto Oyama

Kazuyuki Tsutsumi

Eisuke Kurosawa

Hidetaka Kanahashi

Takehiro Nakaoka

Tetsushi Deura

Fumiaki Kudo

Hiroshi Yokoyama

Shushi Ikeda

Koichi Sakamoto

Yuzo Morikawa

A method includes the production of a primary ingot, the production of a secondary ingot, and the removal of a flux layer. A CaO&#x2014;CaFflux in a content of 3-20 mass % and obtained by mixing 35-95 mass % of CaFwith CaO is added to a Ti&#x2014;Al alloy material including a total of at least 0.1 mass % of oxygen and at least 40 mass % of Al, and the resultant substance is melted by a melting method using a water-cooled copper container in an atmosphere having a pressure of 1.33 Pa or higher and held to produce the primary ingot. The primary ingot is continuously drawn downwards while being melted by a melting method using a bottomless water-cooled copper casting mould in an atmosphere having a pressure of 1.33 Pa or higher to produce the secondary ingot. The flux layer deposited on the surface of the secondary ingot is mechanically removed.

Method for producing Ti-Al alloy

Disclosed herein is a method for deoxidizing an Al&#x2014;Nb&#x2014;Ti alloy, which includes melting and holding an Al&#x2014;Nb&#x2014;Ti alloy containing from 50 to 75 mass % of Al, from 5 to 30 mass % of Nb, and 80 mass % or less in total of Al and Nb by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa to 2.67&#xd7;10Pa at a temperature of 1,900 K or more, thereby decreasing an oxygen content thereof. The Al&#x2014;Nb&#x2014;Ti alloy is prepared using an alloy material formed of an aluminum material, a niobium material and a titanium material and containing oxygen in a total amount of 0.5 mass % or more.

Method for deoxidizing Al&#x2014;Nb&#x2014;Ti alloy

A casting method of an active metal includes, in an induction melting furnace using a water-cooled crucible, tapping a molten metal into a mold from a tapping hole provided at a bottom of the water-cooled copper crucible to cast an ingot of the active metal. In conducting the casting under a casting condition in which the ingot has a diameter (D) of 10 mm or more and a ratio (H/D) of an ingot height H to the ingot diameter D of 1.5 or more and a weight of the molten metal tapped in the casting is 200 kg or less, a temperature of the molten metal in the casting is set to be higher than the melting point of the active metal and a casting velocity V (mm/sec) is controlled to satisfy V&#x2264;0.1H in relation with the ingot height H by adjusting an opening diameter of the tapping hole.

Casting method for active metal

By controlling the temperature (T) of a surface portion () of an ingot () in a contact region () between a mold () and the ingot () and/or a passing heat flux (q) from the surface portion () of the ingot () to the mold () in the contact region (), the thickness (D) in the contact region () of a solidified shell () obtained by the solidification of molten metal () is brought into a predetermined range. Consequently, an ingot having a good casting surface state can be cast.

Continuous casting method for ingot produced from titanium or titanium alloy

Disclosed is a continuous casting method in which a melt obtained by melting titanium or a titanium alloy is poured into a bottomless mold and is drawn downward while being solidified, wherein: the surface of the melt in the mold is heated by horizontally moving a plasma torch over the surface of the melt; thermocouples are provided at a plurality of locations along the circumferential direction of the mold; if the temperature of the mold measured by one of the thermocouples is lower than a target temperature, then the output of the plasma torch is increased when the plasma torch comes close to the location where that thermocouple is installed; and if said temperature is higher than the target temperature, then the output of the plasma torch is decreased when the plasma torch comes close to the location where that thermocouple is installed.

Method for continuously casting ingot made of titanium or titanium alloy

A continuous casting method in which a molten metal obtained by melting titanium or a titanium alloy is injected into a bottomless mold having a rectangular cross-section and withdrawn downward while being caused to solidify, wherein a plasma torch () is caused to rotate in the horizontal direction above the surface of the molten metal () in the mold (), and a horizontally rotating flow is generated by electromagnetic stirring on at least the surface of the molten metal () in the mold (). It is thereby possible to cast a slab in which the casting surface condition is excellent.

Continuous casting method for slab made of titanium or titanium alloy

The continuous casting device according to the present invention enables at least some of a plurality of hearths () to be converted between being hearths () used for titanium, which are used during the continuous casting of titanium ingots, and being hearths () used for titanium alloy, which are used during the continuous casting of titanium alloy ingots. The number of hearths () used for titanium alloy is greater than the number of hearths () used for titanium. Also, the total capacity of the hearths () used for titanium alloy is greater than the total capacity of the hearths () used for titanium. Thus, titanium ingots and titanium alloy ingots can each be continuously cast by means of a single piece of equipment.

Continuous casting method and continuous casting device for titanium ingots and titanium alloy ingots

A mold () has a cooling means () for having the thermal flux at four corner sections () be smaller than the thermal flux at four face sections (). The cooling means () has first channels () which are each embedded in the four corner sections () respectively and which channel cooling water, and second channels () which are each embedded in the four face sections () respectively and which channel cooling water. The distance from the inner peripheral surface of the mold () to the first channels () is greater than the distance from the inner peripheral surface of the mold () to the second channels ().

Mold for continuous casting of titanium or titanium alloy ingot, and continuous casting device provided with same

The present invention is a method for manufacturing a titanium ingot (), the method being characterized by comprising: a step of melting a titanium alloy for a predetermined time by cold crucible induction melting (CCIM); a step of supplying molten titanium () to a cold hearth (), and separating high density inclusions (HDIs) () by precipitation in the cold hearth () while spraying a plasma jet or an electron beam onto the bath surface of the molten titanium (); and a step of supplying a molten titanium starting material from which the HDIs () are separated by precipitation to a mold () to obtain the titanium ingot.

Method for manufacturing titanium ingot

The present invention is a method for manufacturing a titanium ingot (), the method being characterized by comprising: a step of melting a titanium alloy for a predetermined time by cold crucible induction melting (CCIM); a step of supplying molten titanium () to a cold hearth (), and separating high density inclusions (HDIs)() by precipitation in the cold hearth () while spraying a plasma jet or an electron beam onto the bath surface of the molten titanium (); and a step of supplying a molten titanium starting material from which the HDIs () are separated by precipitation to a mold () to obtain the titanium ingot.

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Kobe, Japan

Daisuke Matsuwaka