Abstract: A TiAl alloy material containing: Al: 42.0 atomic % or more and 44.0 atomic % or less; Cu: 0.5 atomic % or more and 2.5 atomic % or less; and Nb: 3.0 atomic % or more and 7.0 atomic % or less, with the balance being Ti and unavoidable impurities, and lamellar grains have an average grain size of 20 ?m or more and 200 ?m or less.

Abstract: A TiAl alloy may be suitable for forging and may be used to produce a TiAl alloy material having excellent oxidation resistance, high-temperature creep strength, excellent hot forgeability, and can be subjected to die forging. The TiAl alloy may contain, in atomic percentage: Ti; Al in a range of from 42.0 to 43.6%; Cu in a range of from 0.5 to 2.0%; and Nb in a range of from 3.0 to 7.0%; and unavoidable impurities.

Abstract: A titanium aluminide alloy material for hot forging has a chemical composition including, by atom, aluminum of 38.0% or greater and 39.9% or less, niobium of 3.0% or greater and 5.0% or less, vanadium of 3.0% or greater and 4.0% or less, carbon of 0.05% or greater and 0.15% or less, and titanium and an inevitable impurity as a residue.

Abstract: A titanium aluminide alloy material for hot forging has a chemical composition including, by atom, aluminum of 43.0% or greater and 45.0% or less, niobium of 4.0% or greater and 6.0% or less, chromium of 1.5% or greater and 3.5% or less, and titanium and an inevitable impurity as a residue.

Abstract: Provided herein are an austenite steel that satisfies desirable strength and desirable castability at the same time, and an austenite steel casting using same. The austenite steel according to an embodiment of the present invention contains Ni: 25 to 50%, Nb: 3.8 to 6.0%, Zr: 0.5% or less, B: 0.001 to 0.05%, Cr: 12 to 25%, Ti: 1.6% or less, Mo: 4.8% or less, and W: 5.2% or less in mass %, and the balance Fe and unavoidable impurities, wherein the parameter Ps represented by the following formula (1) satisfies Ps?38, Ps=8.3[Nb]?7.5[Ti]+2.4[Mo]+3.5[W]??formula (1), where [Nb], [Ti], [Mo], and [W] represent the contents of Nb, Ti, Mo, and W, respectively, in mass %.

Abstract: Provided herein are an austenite steel that satisfies desirable strength and desirable castability at the same time, and an austenite steel casting using same. The austenite steel according to an embodiment of the present invention contains Ni: 25 to 50%, Nb: 3.8 to 6.0%, Zr: 0.5% or less, B: 0.001 to 0.05%, Cr: 12 to 25%, Ti: 1.6% or less, Mo: 4.8% or less, and W: 5.2% or less in mass %, and the balance Fe and unavoidable impurities, wherein the parameter Ps represented by the following formula (1) satisfies Ps?38, Ps=8.3[Nb]?7.5[Ti]+2.4[Mo]+3.5[W]??formula (1), where [Nb], [Ti], [Mo], and [W] represent the contents of Nb, Ti, Mo, and W, respectively, in mass %.

Abstract: An aluminum or aluminum alloy-coated steel material includes base steel; and a coating layer formed on a surface of the base steel and containing by mass % Mg: 6% to 10%, Si: 3% to 7%, Fe: 0.2% to 2%, Mn: 0.02% to 2%, and the balance as Al and incidental impurities, wherein the coating layer has pseudoternary eutectic microstructures of ?Al—Mg2Si—(Al—Fe—Si—Mn) and an area ratio of the pseudoternary eutectic microstructures in the coating layer is at least 30%.

Abstract: An aluminum or aluminum alloy-coated steel material includes base steel; and a coating layer formed on a surface of the base steel and containing by mass % Mg: 6% to 10%, Si: 3% to 7%, Fe: 0.2% to 2%, Mn: 0.02% to 2%, and the balance as Al and incidental impurities, where-in the coating layer has pseudoternary eutectic microstructures of ?Al—Mg2Si—(Al—Fe—Si—Mn) and an area ratio of the pseudoternary eutectic microstructures in the coating layer is at least 30%.

Abstract: A hot-forged TiAl-based alloy having excellent oxidation resistance and high strength at high temperatures, and a process for producing such an alloy. A TiAl-based alloy comprising Al: (40+a) atomic % and Nb: b atomic %, with the remainder being Ti and unavoidable impurities, wherein a and b satisfy formulas (1) and (2) below. 0?a?2??(1) 3+a?b?7+a??(2) Also, a TiAl-based alloy comprising Al: (40+a) atomic % and Nb: b atomic %, and further comprising one or more elements selected from the group consisting of V: c atomic %, Cr: d atomic % and Mo: e atomic %, with the remainder being Ti and unavoidable impurities, wherein a to e satisfy formulas (3) to (9) shown below. 0?a?2??(3) 3+a?b+1.0c+1.8d+3.

Abstract: A TiAl based alloy having excellent strength as well as an improvement in toughness at room temperature, in particular an improvement in impact properties at room temperature, and a production method thereof, and a blade using the same are provided. This TiAl based alloy has a microstructure in which lamellar grains having a mean grain diameter of from 1 to 50 ?m are closely arranged. The alloy composition is Ti-(42-48)Al-(5-10)(Cr and/or V) or Ti-(38-43)Al-(4-10)Mn. The alloy can be obtained by subjecting the alloy to high-speed plastic working in the cooling process, after the alloy has been held in an equilibrium temperature range of the ? phase or the (?+?) phase.

Abstract: A TiAl based alloy having excellent strength as well as an improvement in toughness at room temperature, in particular an improvement in impact properties at room temperature, and a production method thereof, and a blade using the same are provided. This TiAl based alloy has a microstructure in which lamellar grains having a mean grain diameter of from 1 to 50 &mgr;m are closely arranged. The alloy composition is Ti-(42-48)Al-(5-10) (Cr and/or V) or Ti-(38-43)Al-(4-10)Mn. The alloy can be obtained by subjecting the alloy to high-speed plastic working in the cooling process, after the alloy has been held in an equilibrium temperature range of the &agr; phase or the (&agr;+&bgr;) phase.

Abstract: A TiAl based alloy having excellent strength as well as an improvement in toughness at room temperature, in particular an improvement in impact properties at room temperature, and a production method thereof, and a blade using the same are provided. This TiAl based alloy has a microstructure in which lamellar grains having a mean grain diameter of from 1 to 50 &mgr;m are closely arranged. The alloy composition is Ti-(42-48)Al-(5-10) (Cr and/or V) or Ti-(38-43)Al-(4-10)Mn. The alloy can be obtained by subjecting the alloy to high-speed plastic working in the cooling process, after the alloy has been held in an equilibrium temperature range of the &agr; phase or the (&agr;+&bgr;) phase.

Abstract: A TiAl based alloy having excellent strength as well as an improvement in toughness at room temperature, in particular an improvement in impact properties at room temperature, and a production method thereof, and a blade using the same are provided. This TiAl based alloy has a microstructure in which lamellar grains having a mean grain diameter of from 1 to 50 &mgr;m are closely arranged. The alloy composition is Ti-(42-48)Al-(5-10) (Cr and/or V) or Ti-(38-43)Al-(4-10)Mn. The alloy can be obtained by subjecting the alloy to high-speed plastic working in the cooling process, after the alloy has been held in an equilibrium temperature range of the &agr; phase or the (&agr;+&bgr;) phase.

Abstract: The specification discloses chromium-niobium alloys which exhibit improved mechanical properties at high temperatures in the range of 1250.degree. C. and improved room temperature ductility. The alloys contain a Cr.sub.2 Nb-rich intermetallic phase and a Cr-rich phase with an overall niobium concentration in the range of from about 5 to about 18 at. %. The high temperature strength is substantially greater than that of state of the art nickel-based superalloys for enhanced high temperature service. Further improvements in the properties of the compositions are obtained by alloying with rhenium and aluminum; and additional rare-earth and other elements.