Abstract: A method for manufacturing an additively manufactured article, the method comprising subjecting a powder material comprising a first powder containing a precipitation hardening stainless steel and a second powder containing titanium carbide to weaving irradiation with a laser beam to melt and solidify the powder material, thereby laminating at least one hardened clad layer on a base material. In the step for laminating the clad layer, the following requirements are satisfied: 20?A?35, 1.1?B?1.3, and (40% by mass)?R2?(65% by mass). In the formulae, A represents a laser heat input index, B represents a powder feeding rate index, and R2 represents a content ratio of the second powder in the powder material.

Abstract: A method for producing an additively-manufactured article includes: a step for feeding a powdered material onto a base metal, the powdered material being obtained by mixing a first powder containing a stellite alloy and a second powder containing tungsten carbide; a nd a step for irradiating the fed powdered material with a laser beam while weaving the lase r beam, and depositing a cladding layer, obtained by melting and solidifying at least the pow dered material, on the base metal. The step for depositing the cladding layer is performed such that 20?A?35, 2.2?B?2.9, and 5 mass%?R2?15 mass% are satisfied, where A is a laser heat input index, B is a powder feeding rate index, and R2 is the ratio of the second powder contained in the powdered material.

Abstract: A recoater of an additive manufacturing apparatus includes a powder retention section that defines a retention space in which a powder material is retained, and a slit part that has a slit inlet that receives the powder material retained and a slit outlet through which the powder material is discharged. The slit part includes a plate member fixed to the powder retention section by surface contact. A pair of slit inner wall surfaces that is connected to the slit outlet and faces each other is formed within a plate thickness of the plate member.

Abstract: For a slit outlet width d and a slit inclination angle ?, the following relations (1) and (2) are satisfied: d?0.0024×(??75°)2+4.5, and d?Lc?2h/tan ?, wherein ? [°] is a slit inclination angle being an acute angle formed by at least one of slit inner wall surfaces and a slit outlet surface of a slit part, d [mm] is a slit outlet width being a width of a slit outlet formed by the pair of slit inner wall surfaces in a moving direction, h [mm] is a slit height being a shortest distance between the slit outlet and a slit inlet, and Lc [mm] is a retention section width being a width of a powder retention section in the moving direction at a position where the powder retention section is connected to the slit part.

Abstract: A method for manufacturing an additively-manufactured object, includes: an additively-manufacturing step of building a layered body by depositing a weld bead obtained by melting and solidifying a filler metal, the layered body having an opening along a forming direction of the weld bead and an internal space surrounded by the weld bead; and a closing step of forming a closing wall portion connecting an edge portion of the opening with the weld bead for closing. In the additively-manufacturing step, the opening is formed with a width dimension larger than a bead width of the weld bead, and in the closing step, the closing wall portion having a width dimension larger than the bead width is formed by the weld bead to close the opening.

Abstract: A method for depositing a hardened layer includes sequentially depositing a hardened layer formed by supplying a powder material for forming a hardened layer, which is obtained by mixing a plurality of kinds of powders, to a substrate, and melting and solidifying the powder material on/above the substrate. The powder material contains a first powder containing an alloy to be serving as a matrix portion of the hardened layer and a second powder containing a ceramic. The method includes heating the powder material until at least a part of the second powder is melted, to allow at least a part of metal elements contained in the melted second powder to be dissolved in the matrix portion of the hardened layer.

Abstract: A method for depositing a hardened layer includes sequentially depositing a hardened layer. The hardened layer is formed by spraying a powder material for forming a hardened layer, which is obtained by mixing a first powder containing a Stellite alloy with a second powder containing tungsten carbide, toward a substrate, and melting and solidifying the powder material on/above the substrate. As the hardened layer to be formed is away from the substrate in a deposition direction, at least one of a heat input adjustment step and a content adjustment step is performed. The heat input adjustment step is a step of reducing a heat input for the powder material during formation of the hardened layer. The content adjustment step is a step of increasing a content of the second powder in the powder material for the hardened layer.

Abstract: A mold wash is used in a casting method using a lost foam to make a casting having a hole with a diameter of 12 mm or less. The casting method includes determining a thermal decomposition amount ?C(?,t) [wt %] of a resin binder when the mold wash is exposed at a temperature ? [° C.] for a time t [sec], and determining a room temperature transverse rupture strength ?b(?,t) [MPa] of the mold wash after receiving thermal loads, and performing casting with the mold wash having the room temperature transverse rupture strength ?b(?,t) after receiving thermal loads being equal to or larger than a threshold value ?cr [MPa].

Abstract: A mold wash is used in a casting method using a lost foam to make a casting having a hole with a diameter of 12 mm or less. The casting method includes determining a thermal decomposition amount ?C(?,t) [wt %] of a resin binder when the mold wash is exposed at a temperature ? [° C.] for a time t [sec], and determining a room temperature transverse rupture strength ?b(?,t) [MPa] of the mold wash after receiving thermal loads, and performing casting with the mold wash having the room temperature transverse rupture strength ?b(?,t) after receiving thermal loads being equal to or larger than a threshold value ?cr [MPa].

Abstract: For continuously casting an ingot of titanium or titanium alloy, molten titanium or titanium alloy is poured into a top opening of a bottomless mold with a circular cross-sectional shape, the solidified molten metal in the mold is pulled downward from the mold, a plurality of plasma torches disposed on an upper side of molten metal in the mold such that their centers are located directly vertically above the molten metal in the mold, are operated to generate plasma arcs that heat the molten metal in the mold, and the plasma torches are moved in a horizontal direction above a melt surface of the molten metal in the mold, along a trajectory located directly vertically above the molten metal in the mold, while keeping a mutual distance between the respective plasma torches such that the plasma torches do not interfere with each other.

Abstract: The present invention provides a method for casting a slab having a good cast surface. The method includes heating the surface of molten metal on a metal inlet side of a mold by a first heat source so that the following formulas: q?0.87 and c?11.762q+0.3095 are satisfied where c is a cycle time [sec] of turning movement of the first heat source, and q is an average amount of heat input [MW/m2] determined by accumulating an amount of heat input applied by at least the first heat source to the contact region between the upper surface of the slab on the metal inlet side and the mold, along the path of turning movement of the first heat source, and dividing the resultant accumulated value by the cycle time c.

Abstract: In the present invention the torch movement period is 20-40 seconds, with the torch movement period being the time required to move plasma torches (which heat the surface of molten metal in the casting mold) one time. The average heat input amount at multiple sites, which are obtained by dividing the initial solidification portion (which is where the molten metal makes contact with the casting mold and first solidifies) into multiple sites in the circumferential direction of the casting mold, is 1.0-2.0 MW/m2. The molten metal advection time, which is the time required for electromagnetically stirred molten metal to travel the length of the torch heating region of the surface of the molten metal in the lengthwise direction of the casting mold, is 3.5 seconds or less.

Abstract: In the present invention the torch movement period is 20-40 seconds, with the torch movement period being the time required to move plasma torches (which heat the surface of molten metal in the casting mold) one time. The average heat input amount at multiple sites, which are obtained by dividing the initial solidification portion (which is where the molten metal makes contact with the casting mold and first solidifies) into multiple sites in the circumferential direction of the casting mold, is 1.0-2.0 MW/m2. The molten metal advection time, which is the time required for electromagnetically stirred molten metal to travel the length of the torch heating region of the surface of the molten metal in the lengthwise direction of the casting mold, is 3.5 seconds or less.

Abstract: The present invention provides a method for casting a slab with good cast surface quality. The method includes pouring molten metal 8 into a mold 2 from one of the paired shorter sides of the mold 2 while allowing superheat ?T [° C.], which is a temperature difference obtained by subtracting the melting point Tm [° C.] of the raw material from the temperature Tin [° C.] of the molten material on the surface of the molten metal in the mold and at the pouring point of the molten metal, to satisfy the following Formula (1) and Formula (2): 0.0014?T2 +0.0144?T+699.45>800 ??Formula (1) 0.0008?T2 +0.2472?T+853.

Abstract: The present invention provides a method for casting a slab having a good cast surface. The method includes heating the surface of molten metal on a metal inlet side of a mold by a first heat source so that the following formulas: q?0.87 and c?11.762q+0.3095 are satisfied where c is a cycle time [sec] of turning movement of the first heat source, and q is an average amount of heat input [MW/m2] determined by accumulating an amount of heat input applied by at least the first heat source to the contact region between the upper surface of the slab on the metal inlet side and the mold, along the path of turning movement of the first heat source, and dividing the resultant accumulated value by the cycle time c.

Abstract: The present invention provides a method for casting a slab with good cast surface quality. The method includes pouring molten metal 8 into a mold 2 from one of the paired shorter sides of the mold 2 while allowing superheat ?T [° C.], which is a temperature difference obtained by subtracting the melting point Tm [° C.] of the raw material from the temperature Tin [° C.] of the molten material on the surface of the molten metal in the mold and at the pouring point of the molten metal, to satisfy the following Formula (1) and Formula (2): 0.0014?T2 +0.0144?T+699.45>800 ??Formula (1) 0.0008?T2 +0.2472?T+853.

Abstract: Provided is a device for titanium continuous casting (1) capable, even when continuously casting large diameter titanium ingots or titanium alloy ingots, of suppressing component segregation thereof. The device for titanium continuous casting (1) comprises: a mold (3) having an upper section having a circular upper opening (3a) for pouring in molten metal (6), and a bottom section having a lower opening for continuously drawing ingots (11); and a plurality of plasma torches (4, 5) to heat the molten metal in the mold (3) from the upper opening (3a) side. The plurality of plasma torches (4, 5) are disposed so that the amount of heat input to the molten metal (6) present in the outer circumference enclosing the center of the upper opening (3a) is greater than the amount of heat input to the molten metal (6) present in the center of the upper opening (3a).

Abstract: In the present invention the torch movement period is 20-40 seconds, with the torch movement period being the time required to move plasma torches (which heat the surface of molten metal in the casting mold) one time. The average heat input amount at multiple sites, which are obtained by dividing the initial solidification portion (which is where the molten metal makes contact with the casting mold and first solidifies) into multiple sites in the circumferential direction of the casting mold, is 1.0-2.0 MW/m2. The molten metal advection time, which is the time required for electromagnetically stirred molten metal to travel the length of the torch heating region of the surface of the molten metal in the lengthwise direction of the casting mold, is 3.5 seconds or less.

Abstract: For continuously casting an ingot of titanium or titanium alloy, molten titanium or titanium alloy is poured into a top opening of a bottomless mold with a circular cross-sectional shape, the solidified molten metal in the mold is pulled downward from the mold, a plurality of plasma torches disposed on an upper side of molten metal in the mold such that their centers are located directly vertically above the molten metal in the mold, are operated to generate plasma arcs that heat the molten metal in the mold, and the plasma torches are moved in a horizontal direction above a melt surface of the molten metal in the mold, along a trajectory located directly vertically above the molten metal in the mold, while keeping a mutual distance between the respective plasma torches such that the plasma torches do not interfere with each other.

Abstract: By controlling the temperature (TS) of a surface portion (11a) of an ingot (11) in a contact region (16) between a mold (2) and the ingot (11) and/or a passing heat flux (q) from the surface portion (11a) of the ingot (11) to the mold (2) in the contact region (16), the thickness (D) in the contact region (16) of a solidified shell (13) obtained by the solidification of molten metal (12) is brought into a predetermined range. Consequently, an ingot having a good casting surface state can be cast.