Abstract: A method of producing a Ni-based super heat-resistant alloy in which a hot working material is subjected to hot working with a mold is provided. The hot working material consists of, in mass%, 0.001 to 0.050% of C, 1.0% to 4.0% of Al, 3.0% to 7.0% of Ti, 12% to 18% of Cr, 12% to 30% of Co, 1.5% to 5.5% of Mo, 0.5% to 2.5% of W, 0.001% to 0.050% of B, 0.001% to 0.100% of Zr, 0% to 0.01% of Mg, 0% to 5% of Fe, 0% to 3% of Ta, 0% to 3% of Nb, and the remainder of Ni and impurities. The method includes: heating and holding the hot working material in a temperature range of 950° C. to 1150° C. for 1 hour or longer; and performing hot working on the material with the mold that is heated to a temperature range of 800° C. to 1150° C.

Abstract: A production method for an Fe—Ni based heat-resistant superalloy inhibits abnormal grain growth and yields a fine crystal grain structure having an ASTM crystal grain size number of 9 or greater. The production method comprises at least a hot working step in which a material having a prescribed composition is subjected to hot working, wherein the hot working step includes at least a step in which the above material of 930 to 1010° C. is subjected to hot working so that the relation of (effective strain)?0.139×(effective strain rate(/sec))?0.30 is satisfied in the entirety of the above material.

Abstract: A method of producing a Ni-based superalloy is provided. A hot working material is used and consisting of a specific composition and has a solvus temperature of a ?? phase of 1050° C. or more. The method includes: performing heating in a temperature of 980° C. to 1050° C. with an upper limit of ?30° C. from the solvus temperature of the ?? phase, for 10 hours or longer; and performing hot working on the material at a working speed of a strain rate of 2.0/second or more in the above temperature range.

Abstract: A method of producing a Ni-based superalloy is provided. A hot working material is used and consisting of a specific composition and has a solvus temperature of a ?? phase of 1050° C. or more. The method includes: performing heating in a temperature of 980° C. to 1050° C. with an upper limit of ?30° C. from the solvus temperature of the ?? phase, for 10 hours or longer; and performing hot working on the material at a working speed of a strain rate of 2.0/second or more in the above temperature range.

Abstract: A method of producing a Ni-based super heat-resistant alloy in which a hot working material is subjected to hot working with a mold is provided. The hot working material consists of, in mass %, 0.001 to 0.050% of C, 1.0% to 4.0% of Al, 3.0% to 7.0% of Ti, 12% to 18% of Cr, 12% to 30% of Co, 1.5% to 5.5% of Mo, 0.5% to 2.5% of W, 0.001% to 0.050% of B, 0.001% to 0.100% of Zr, 0% to 0.01% of Mg, 0% to 5% of Fe, 0% to 3% of Ta, 0% to 3% of Nb, and the remainder of Ni and impurities. The method includes: heating and holding the hot working material in a temperature range of 950° C. to 1150° C. for 1 hour or longer; and performing hot working on the material with the mold that is heated to a temperature range of 800° C. to 1150° C.

Abstract: There is provided a method for producing a Ni-based heat-resistant superalloy a primary ?? phase with an average particle size of at least 500 nm comprising the steps of: providing a material to be hot-worked having a composition consisting of, by mass, 0.001 to 0.05% C, 1.0 to 4.0% Al, 4.5 to 7.0% Ti, 12 to 18% Cr, 14 to 27% Co, 1.5 to 4.5% Mo, 0.5 to 2.5% W, 0.001 to 0.05% B, 0.001 to 0.1% Zr, and the balance of Ni with inevitable impurities; heating the material to be hot-worked in a temperature having a range of 1,130 to 1,200° C. for at least 2 hours; cooling the material to be hot-worked heated by the heating step to a hot working temperature or less at a cooling rate of at most 0.03° C./second; and subjecting the material to be hot-worked to hot working after the cooling step.

Abstract: There is provided an Ni-base super alloy which is used for airplane engines and gas turbines for power generation and has favorable mechanical properties at high temperature. The Ni-base super alloy contains 0.001 to 0.1 mass % of C, 1.0 to 4.0 mass % of Al, 2.0 to 4.5 mass % of Ti, 12.0 to 18.0 mass % of Cr, 11.1 to 18.0 mass % of Co, 1.2 to 12.0 mass % of Fe, 1.5 to 6.5 mass % of Mo, 0.5 to 6.0 mass % of W, 0.1 to 3.0 mass % of Nb, 0.001 to 0.05 mass % of B, 0.001 to 0.1 mass % of Zr, and Ni and impurities as a remainder.

Abstract: There is provided an Ni-base super alloy which is used for airplane engines and gas turbines for power generation and has favorable mechanical properties at high temperature. The Ni-base super alloy contains 0.001 to 0.1 mass % of C, 1.0 to 4.0 mass % of Al, 2.0 to 4.5 mass % of Ti, 12.0 to 18.0 mass % of Cr, 11.1 to 18.0 mass % of Co, 1.2 to 12.0 mass % of Fe, 1.5 to 6.5 mass % of Mo, 0.5 to 6.0 mass % of W, 0.1 to 3.0 mass % of Nb, 0.001 to 0.05 mass % of B, 0.001 to 0.1 mass % of Zr, and Ni and impurities as a remainder.

Abstract: A production method for an Fe—Ni based heat-resistant superalloy inhibits abnormal grain growth and yields a fine crystal grain structure having an ASTM crystal grain size number of 9 or greater. The production method comprises at least a hot working step in which a material having a prescribed composition is subjected to hot working, wherein the hot working step includes at least a step in which the above material of 930 to 1010° C. is subjected to hot working so that the relation of (effective strain)?0.139×(effective strain rate(/sec))?0.30 is satisfied in the entirety of the above material.

Abstract: There is provided a method for producing a Ni-based heat-resistant superalloy a primary ?? phase with an average particle size of at least 500 nm comprising the steps of: providing a material to be hot-worked having a composition consisting of, by mass, 0.001 to 0.05% C, 1.0 to 4.0% Al, 4.5 to 7.0% Ti, 12 to 18% Cr, 14 to 27% Co, 1.5 to 4.5% Mo, 0.5 to 2.5% W, 0.001 to 0.05% B, 0.001 to 0.1% Zr, and the balance of Ni with inevitable impurities; heating the material to be hot-worked in a temperature having a range of 1,130 to 1,200° C. for at least 2 hours; cooling the material to be hot-worked heated by the heating step to a hot working temperature or less at a cooling rate of at most 0.03° C./second; and subjecting the material to be hot-worked to hot working after the cooling step.

Abstract: Provided is an Ni-base alloy excellent in strength, ductility and other properties through the resolution of micro-segregation. Also provided is a process for manufacturing an Ni-base alloy containing by mass C:0.15% or less, Si:1% or less, Mn:1% or less, Cr:10 to 24%, Mo+(1/2)W (where Mo may be contained either alone or as an essential component):5 to 17%, Al:0.5 to 1.8%, Ti:1 to 2.5%, Mg:0.02% or less, and either B:0.02% or less and/or Zr:0.2% or less at an Al/(Al+0.56Ti) ratio of 0.45 to 0.70 with the balance consisting of Ni and impurities, which comprises subjecting, at least one time, an Ni-base alloy material which is prepared by vacuum melting and has the above composition to homogenization heat treatment at 1160 to 1220° C. for 1 to 100 hours. The Mo segregation ratio of the alloy is controlled to 1 to 1.17 by the homogenization heat treatment.

Abstract: To provide an inexpensive heat-resisting steel for engine valves by causing Fe-based heat-resisting steel to exhibit high temperature strength not inferior to that of Ni-based heat-resisting steel. A heat-resisting steel for engine valves excellent in high temperature strength containing, in % by mass, C: 0.20 to 0.50%, Si: 1.0% or less, Mn: 5.0% or less, P: 0.1 to 0.5%, Ni: 8.0 to 15.0%, Cr: 16.0 to 25.0%, Mo: 2.0 to 5.0%, Cu: 0.5% or less, Nb: 1.0% or less (including 0%), W: 8.0% or less (including 0%), N: 0.02 to 0.2%, B: 0.01% or less, and remnants of Fe and impurities, wherein the heat-resisting steel for engine valves satisfies formulae below: 442P(%)+12Mo(%)+5W(%)+7Nb(%)+328N(%)+171?300??Formula (1) ?38.13P(%)+1.06Mo(%)+0.13W(%)+9.64Nb(%)+13.52N(%)+4.83?0.12??Formula (2).

Abstract: Disclosed is a low-thermal-expansion Ni-based super-heat-resistant alloy for a boiler, which has excellent high-temperature strength. The alloy can be welded without the need of carrying out any aging treatment. The alloy has a Vickers hardness value of 240 or less. The alloy comprises (by mass) C in an amount of 0.2% or less, Si in an amount of 0.5% or less, Mn in an amount of 0.5% or less, Cr in an amount of 10 to 24%, one or both of Mo and W in such an amount satisfying the following formula: Mo+0.5 W=5 to 17%, Al in an amount of 0.5 to 2.0%, Ti in an amount of 1.0 to 3.0%, Fe in an amount of 10% or less, and one or both of B and Zr in an amount of 0.02% or less (excluding 0%) for B and in an amount of 0.2% or less (excluding 0%) for Zr, with the remainder being 48 to 78% of Ni and unavoidable impurities.

Abstract: An alloy to be surface-coated, which can keep excellent hardness of 58HRC or above even when the amount of an alloying element added is reduced or even when the alloy is heated to a temperature of as high as 400 to 500° C.; and sliding members produced by forming a hard film on the surface of the alloy. An alloy to be surface-coated, the surface of which is to be covered with a hard film, which alloy contains by mass C: 0.5 to 1.2%, Si: 2.0% or below, Mn: 1.0% or below, Cr: 5.0 to 14.0%, Mo+1/2 W: 0.5 to 5.0%, and N: more than 0.015 to 0.1% with the balance being Fe and impurities, preferably such an alloy which contains by mass C: 0.6 to 0.85%, Si: 0.1 to 1.5%, Mn: 0.2 to 0.8%, Cr: 7.0 to 11.0%, Mo+1/2 W: 1.0 to 4.0%, and N: 0.04 to 0.08%.

Abstract: Provided is a coated-surface sliding part having excellent adhesion of a hard coating, and a method for producing the same part. The coated-surface sliding part is a sliding part wherein a hard coating is formed by physical deposition on the surface of a base material formed from, by mass percent, C 0.5 to 0.8%, Si 0.1 to 1.5%, Mn 0.2 to 1.0%, Cr 8.0 to 13.5%, Mo and/or W 0.5 to 4.0% in terms of (Mo+ 1/2 W), and N 0.01 to 0.1%, with the remainder being Fe and impurities. The physically deposited coating is a titanium metal coating further covered by a diamond-like carbon coating. The method for producing a coated-surface part involves sputtering in order to apply the physically deposited coating, which consists of the titanium metal coating and then the diamond-like carbon coating which forms the surface layer, to the surface of the base material having the aforementioned composition. The base material is preferably subjected to argon gas bombardment prior to application of the physically deposited coating.

Abstract: To provide an inexpensive heat-resisting steel for engine valves by causing Fe-based heat-resisting steel to exhibit high temperature strength not inferior to that of Ni-based heat-resisting steel. A heat-resisting steel for engine valves excellent in high temperature strength containing, in % by mass, C: 0.20 to 0.50%, Si: 1.0% or less, Mn: 5.0% or less, P: 0.1 to 0.5%, Ni: 8.0 to 15.0%, Cr: 16.0 to 25.0%, Mo: 2.0 to 5.0%, Cu: 0.5% or less, Nb: 1.0% or less (including 0%), W: 8.0% or less (including 0%), N: 0.02 to 0.2%, B: 0.01% or less, and remnants of Fe and impurities, wherein the heat-resisting steel for engine valves satisfies formulae below: 442P(%)+12Mo(%)+5W(%)+7Nb(%)+328N(%)+171?300??Formula (1) ?38.13P(%)+1.06Mo(%)+0.13W(%)+9.64Nb(%)+13.52N(%)+4.83?0.

Abstract: Provided is an Ni-base alloy excellent in strength, ductility and other properties through the resolution of micro-segregation. Also provided is a process for manufacturing an Ni-base alloy containing by mass C: 0.15% or less, Si: 1% or less, Mn: 1% or less, Cr: 10 to 24%, Mo+(½)W (where Mo may be contained either alone or as an essential component): 5 to 17%, Al: 0.5 to 1.8%, Ti: 1 to 2.5%, Mg: 0.02% or less, and either B: 0.02% or less and/or Zr: 0.2% or less at an Al/(Al+0.56Ti) ratio of 0.45 to 0.70 with the balance consisting of Ni and impurities, which comprises subjecting, at least one time, an Ni-base alloy material which is prepared by vacuum melting and has the above composition to homogenization heat treatment at 1160 to 1220° C. for 1 to 100 hours. The Mo segregation ratio of the alloy is controlled to 1 to 1.17 by the homogenization heat treatment.

Abstract: An alloy to be surface-coated, which can keep excellent hardness of 58HRC or above even when the amount of an alloying element added is reduced or even when the alloy is heated to a temperature of as high as 400 to 500° C.; and sliding members produced by forming a hard film on the surface of the alloy. An alloy to be surface-coated, the surface of which is to be covered with a hard film, which alloy contains by mass C: 0.5 to 1.2%, Si: 2.0% or below, Mn: 1.0% or below, Cr: 5.0 to 14.0%, Mo+1/2 W: 0.5 to 5.0%, and N: more than 0.015 to 0.1% with the balance being Fe and impurities, preferably such an alloy which contains by mass C: 0.6 to 0.85%, Si: 0.1 to 1.5%, Mn: 0.2 to 0.8%, Cr: 7.0 to 11.0%, Mo+1/2 W: 1.0 to 4.0%, and N: 0.04 to 0.08%.

Abstract: Disclosed is a low-thermal-expansion Ni-based super-heat-resistant alloy for a boiler, which has excellent high-temperature strength. The alloy can be welded without the need of carrying out any aging treatment. The alloy has a Vickers hardness value of 240 or less. The alloy comprises (by mass) C in an amount of 0.2% or less, Si in an amount of 0.5% or less, Mn in an amount of 0.5% or less, Cr in an amount of 10 to 24%, one or both of Mo and W in such an amount satisfying the following formula: Mo+0.5 W=5 to 17%, Al in an amount of 0.5 to 2.0%, Ti in an amount of 1.0 to 3.0%, Fe in an amount of 10% or less, and one or both of B and Zr in an amount of 0.02% or less (excluding 0%) for B and in an amount of 0.2% or less (excluding 0%) for Zr, with the remainder being 48 to 78% of Ni and unavoidable impurities.

Abstract: Provided is a steel for separators of solid-oxide type fuel cells, which forms oxide films having good electrical conductivity at 700 to 950° C. or so, has good oxidation resistance and, in particular, resistance to exfoliation even in the case of long hours of use, is excellent in impact properties at room temperature, shows a small difference in thermal expansion from the electrolyte, and is inexpensive. This steel for separators of solid-oxide fuel cells includes, by mass %, not more than 0.2% C, not more than 1.0% Si, not more than 1.0% Mn, not more than 2% Ni, 15 to 30% Cr, not more than 1% Al, one or more elements selected from the group of not more than 0.5% Y, not more than 0.2% REM and not more than 1% Zr, and the balance of Fe and unavoidable impurities. In this steel, amounts of S, O, N and B in the unavoidable impurities are restricted to not more than 0.015%, not more than 0.010%, not more than 0.050% and not more than 0.