Abstract: The present invention provides a hot-forgeable Ni-based superalloy excellent in high temperature strength, including, in terms of % by mass: C: more than 0.001% and less than 0.100%, Cr: 11.0% or more and less than 19.0%, Co: 0.5% or more and less than 22.0%, Fe: 0.5% or more and less than 10.0%, Si: less than 0.1%, Mo: more than 2.0% and less than 5.0%, W: more than 1.0% and less than 5.0%, Mo+½W: 2.5% or more and less than 5.5%, S: 0.010% or less, Nb: 0.3% or more and less than 2.0%, Al: more than 3.00% and less than 6.50%, and Ti: 0.20% or more and less than 2.49%, with the balance being Ni and unavoidable impurities, in which (Ti/Al)×10 is 0.2 or more and less than 4.0 in terms of atomic ratio, and in which Al+Ti+Nb is 8.5% or more and less than 13.0% in terms of atomic %.

Abstract: Provided is a maraging steel excellent in fatigue characteristics, including, in terms of % by mass: C: ?0.015%, Ni: from 12.0 to 20.0%, Mo: from 3.0 to 6.0%, Co: from 5.0 to 13.0%, Al: from 0.01 to 0.3%, Ti: from 0.2 to 2.0%, O: ?0.0020%, N: ?0.0020%, and Zr: from 0.001 to 0.02%, with the balance being Fe and unavoidable impurities.

Abstract: Provided is a precipitation hardened Fe—Ni alloy having the following constitutions: (1) the precipitation hardened Fe—Ni alloy including: from 0.01 to 0.08% by mass of C, from 0.02 to 1.0% by mass of Si, not more than 1.0% by mass of Mn, from 36.0 to 41.0% by mass of Ni, 14.0 or more and less than 20.0% by mass of Cr, from 0.01 to 3.0% by mass of Mo, from 0.1 to 1.0% by mass of Al, from 1.0 to 2.5% by mass of Ti, and from 2.0 to 3.5% by mass of Nb, with the balance being Fe and unavoidable impurities; (2) the precipitation hardened Fe—Ni alloy satisfying the following formulae: Ni?6×Nb+17 and Nb/(Ti+Al)?0.8.

Abstract: The object of the present invention is to provide a heat-resistant steel for exhaust valves, having relatively small Ni content, high mechanical characteristics (for example, tensile strength, fatigue strength, wear resistance and hardness) at high temperature, and excellent oxidation resistance. The present invention provides a heat-resistant steel for exhaust valves, which includes: 0.45?C<0.60 mass %, 0.30<N<0.50 mass %, 19.0?Cr<23.0 mass %, 5.0?Ni<9.0 mass %, 8.5?Mn<10.0 mass %, 2.5?Mo<4.0 mass %, 0.01?Si<0.50 mass %, and 0.01?Nb<0.30 mass %, with the balance being Fe and unavoidable impurities, in which the steel satisfies 0.02?Nb/C<0.70 and satisfies 4.5?Mo/C<8.9.

Abstract: The present invention provides a nonmagnetic high-hardness alloy having a Ni-based alloy composition containing; by weight %, C of 0.1% or less: Si of 2.0% or less; Mn of 2.0% or less; P of 0.03% or less; S of 0.01% or less; Cr of 30 to 45%; Al of 1.5 to 5.0%; and a balance of unavoidable impurities and Ni, the nonmagnetic high-hardness alloy being subjected to cold or warm plastic working and then ageing treatment, and a method for producing the nonmagnetic high-hardness alloy.

Abstract: The present invention provides a maraging steel containing: 0.10?C?0.30 mass %, 6.0?Ni?9.4 mass %, 11.0?Co?20.0 mass %, 1.0?Mo?6.0 mass %, 2.0?Cr?6.0 mass %, 0.5?Al?1.3 mass %, and Ti?0.1 mass %, with the balance being Fe and unavoidable impurities, and satisfying 1.00?A?1.08, in which A is 0.95+0.35×[C]?0.0092×[Ni]+0.011×[Co]?0.02×[Cr]?0.001×[Mo], where [C] indicates a content (mass %) of C, [Ni] indicates a content (mass %) of Ni, [Co] indicates a content (mass %) of Co, [Cr] indicates a content (mass%) of Cr, and [Mo] indicates a content (mass%) of Mo, respectively, The maraging steel has a tensile strength of 2,300 MPa or more and is also excellent in the toughness/ductility and fatigue characteristics.

Abstract: The present invention aim at providing a steel for steam turbine blades which is excellent in terms of strength and toughness. The steel of the present invention has a composition which contains, in terms of % by mass, 0.02-0.10% of C, up to 0.25% of Si, 0.001-0.10% of Mn, up to 0.010% of P, up to 0.010% of S, 8.5-10.0% of Ni, 10.5-13.0% of Cr, 2.0-2.5% of Mo, 0.001-0.010% of N, 1.15-1.50% of Al, less than 0.10% of Cu, up to 0.20% of Ti, and the remainder being incidental impurities and Fe, and which satisfies 6.0?Ni/Al?8.0, 9.0?Nieq?11.0 and 17.0?Creq?19.0, in which Nieq=[Ni]+0.11[Mn]?0.0086([Mn]2)+0.44[Cu]+18.4[N]+24.5[C] Creq=[Cr]+1.21[Mo]+0.48[Si]+2.2[Ti]+2.48[A1].

Abstract: A Co-based alloy containing not less than 0.001 mass % and less than 0.100 mass % of C, not less than 9.0 mass % and less than 20.0 mass % of Cr, not less than 2.0 mass % and less than 5.0 mass % of Al, not less than 13.0 mass % and less than 20.0 mass % of W, and not less than 39.0 mass % and less than 55.0 mass % of Ni, with the remainder being made up by Co and unavoidable impurities, wherein the contents of Mo, Nb, Ti and Ta which are included in the unavoidable impurities are as follows: Mo<0.010 mass %, Nb<0.010 mass %, Ti<0.010 mass %, and Ta<0.010 mass %.

Abstract: The present invention relates to a low thermal expansion Ni-base superalloy containing, in terms of mass %, C: 0.15% or less; Si: 1% or less; Mn: 1% or less; Cr: 5% or more but less than 20%; at least one of Mo, W and Re, in which Mo+½(W+Re) is 5% or more but less than 20%; W: 10% or less; Al: 0.1 to 2.5%; Ti: 0.10 to 0.95%; Nb+½Ta: 1.5% or less; B: 0.001 to 0.02%; Zr: 0.001 to 0.2%; Fe: 4.0% or less; and a balance of inevitable impurities and Ni, in which the total amount of Al, Ti, Nb and Ta is 2.0 to 6.5% in terms of atomic %. The low thermal expansion Ni-base superalloy of the present invention has a thermal expansion coefficient almost equal to that of 12 Cr ferritic steel, excellent high temperature strength, excellent corrosion and oxidation resistance, good hot-workability, and excellent weldability.

Abstract: The present invention relates to a high-hardness hardfacing alloy powder, containing: 0.5<C?3.0 mass %, 0.5?Si?5.0 mass %, 10.0?Cr?30.0 mass %, and 16.0<Mo?40.0 mass %, with the balance being Co and unavoidable impurities, wherein a total amount of Mo and Cr satisfies 40.0?Mo+Cr?70.0 mass %. The high-hardness hardfacing alloy powder according to the present invention may further contain at least one element selected from the group consisting of: Ca?0.03 mass %, P?0.03 mass %, Ni?5.0 mass % and Fe?5.0 mass %. The high-hardness hardfacing alloy powder according to the present invention can be employed for build-up welding of a face part of a valve used in various internal combustion engines, automotive engines, steam turbines, heat exchangers, heating furnaces and the like.

Abstract: A method for producing a low thermal expansion Ni-base superalloy including the steps of subjecting the alloy to a solution heat treatment under the condition of at a temperature of 1000 to 1200° C. and subjecting the alloy to either a carbide stabilizing treatment for making aggregated carbides on grain boundaries and stabilizing the carbides under the conditions of at a temperature of not less than 850° C. and less than 1000° C. and for 1 to 50 hours, or a carbide stabilizing treatment for making aggregated carbides on grain boundaries and stabilizing the carbides by cooling from the temperature in the solution heat treatment to 850° C. at a cooling rate of 100° C. or less per hour. The method also including the steps of subjecting the alloy to a first aging treatment for precipitating y? phase under the conditions of at a temperature of 720 to 900° C.

Abstract: The present invention provides a heat resistant steel for an exhaust valve, containing: more than 0.50% by mass but less than 0.80% by mass of C, more than 0.30% by mass but less than 0.60% by mass of N, 17.0% by mass or more but less than 25.0% by mass of Cr, 4.0% by mass or more but less than 12.0% by mass of Ni, 7.0% by mass or more but less than 14.0% by mass of Mn, 2.0% by mass or more but less than 6.0% by mass of Mo, more than 0.5% by mass but less than 1.5% by mass of Si, and 0.025% by mass or more but less than 1.0% by mass of Nb, with the balance consisting of Fe and unavoidable impurities, in which a content of P contained in the unavoidable impurities is regulated to less than 0.03% by mass, a total content of C and N is from 0.85% by mass to 1.3% by mass, and a ratio of the content of Nb to the content of C is 0.05 or more but less than 1.8.

Abstract: The present invention provides: a ferritic stainless steel cast iron including: Fe as a main component; C: 0.20 to 0.40 mass %; Si: 1.00 to 3.00 mass %; Mn: 0.30 to 3.00 mass %; Cr: 12.0 to 30.0 mass %; and one of Nb and V, or both of Nb and V in total: 1.0 to 5.0 mass %, the ferritic stainless steel cast iron satisfying the following formula (1): 1400?1562.3?{133WC+14WSi+5WMn+10(WNb+WV)}?1480??(1) wherein, WC (mass %), WSi (mass %), WMn (mass %), WCr (mass %), WNb (mass %), WV (mass %) and WCu (mass %) are contents of C, Si, Mn, Cr, Nb, V and Cu, respectively; a process for producing a cast part from the ferritic cast steel; and the cast part.

Abstract: The present invention provides a high corrosion-resistant, high-strength and non-magnetic stainless steel containing: C: 0.01% to 0.05% by mass, Si: 0.05% to 0.50% by mass, Mn: more than 16.0% by mass but 19.0% by mass or less, P: 0.040% by mass or less, S: 0.010% by mass or less, Cu: 0.50% to 0.80% by mass, Ni: 3.5% to 5.0% by mass, Cr: 17.0% to 21.0% by mass, Mo: 1.80% to 3.50% by mass, B: 0.0010% to 0.0050% by mass, O: 0.010% by mass or less, and N: 0.45% to 0.65% by mass, with the balance substantially composed of Fe and unavoidable impurities, the steel satisfying the following equations (1) to (4): [Cr]+3.3×[Mo]+16×[N]?30 ??(1) [Cr]/[C]?330 ??(2) [Cr]/[Mn]>1.0 ??(3) ([Ni]+3×[Cu])/([Cr]+[Mo])>0.25 ??(4) wherein [Cr], [Mo], [N], [C], [Mn], [Ni] and [Cu] represent the content of Cr, the content of Mo, the content of N, the content of C, the content of Mn, the content of Ni, and the content of Cu in the steel in terms of mass %, respectively.

Abstract: Disclosed is a heat resistant cast steel having not only good heat resistance but also good thermal fatigue resistance, which is suitable as the material for engine parts, particularly, such as exhaust gas manifold and turbo-housing, which are repeatedly exposed to such a high temperature as 900° C. or higher. The heat resistant cast steel comprises, by weight percent, C: 0.2-1.0%, Ni: 8.0-45.0%, Cr: 15.0-30.0%, W: up to 10% and Nb: 0.5-3.0%, provided that [%C]-0.13[%Nb]: 0.05-0.95%, the balance being Fe and inevitable impurities, and the cast structure contains dispersed therein, by atomic percent, MC-type carbides: 0.5-3.0% and M23C6-type carbides: 0.5-10.0%. The matrix of the steel is an austenitic phase mainly composed of Fe—Ni—Cr and the steel has the mean coefficient of thermal expansion in the range from room temperature to 1050° C. up to 20.0×10?4 and a tensile strength in the temperature range up to 1050° C. 50 MPa or higher.

Abstract: The present invention relates to a low thermal expansion Ni-base superalloy containing, in terms of mass %, C: 0.15% or less; Si: 1% or less; Mn: 1% or less; Cr: 5% or more but less than 20%; at least one of Mo, W and Re, in which Mo+½(W+Re) is 5% or more but less than 20%; W: 10% or less; Al: 0.1 to 2.5%; Ti: 0.10 to 0.95%; Nb+½Ta: 1.5% or less; B: 0.001 to 0.02%; Zr: 0.001 to 0.2%; Fe: 4.0% or less; and a balance of inevitable impurities and Ni, in which the total amount of Al, Ti, Nb and Ta is 2.0 to 6.5% in terms of atomic %. The low thermal expansion Ni-base superalloy of the present invention has a thermal expansion coefficient almost equal to that of 12 Cr ferritic steel, excellent high temperature strength, excellent corrosion and oxidation resistance, good hot-workability, and excellent weldability.

Abstract: The present invention provides a Ni-based super alloy including, by mass %, C: 0.01 to 0.15%; Si: 1% or less; Mn: 1% or less; P: 0.02% or less; S: 0.01% or less; Co: less than 0.10%; Cr: 16 to 22%; Mo: 4 to 10%; W: 5% or less; Al: 1.2 to 2.5%; Ti: 2.4 to 4%; B: 0.001 to 0.05%; Zr: 0.01 to 0.5%; Fe: 1% or less; and a balance of Ni and inevitable impurities.

Abstract: The present invention provides: a ferritic stainless steel cast iron including: Fe as a main component; C: 0.20 to 0.40 mass %; Si: 1.00 to 3.00 mass %; Mn: 0.30 to 3.00 mass %; Cr: 12.0 to 30.0 mass %; and one of Nb and V, or both of Nb and V in total: 1.0 to 5.0 mass %, the ferritic stainless steel cast iron satisfying the following formula (1): 1400?1562.3?{133WC+14WSi+5WMn+10(WNb+WV)}?1480??(1) wherein, WC (mass %), WSi (mass %), WMn (mass %), WCr (mass %), WNb (mass %), WV (mass %) and WCu (mass %) are contents of C, Si, Mn, Cr, Nb, V and Cu, respectively; a process for producing a cast part from the ferritic cast steel; and the cast part.

Abstract: The present invention provides a nonmagnetic high-hardness alloy having a Ni-based alloy composition containing; by weight%, C of 0.1% or less: Si of 2.0% or less; Mn of 2.0% or less; P of 0.03% or less; S of 0.01% or less; Cr of 30 to 45%; Al of 1.5 to 5.0%; and a balance of unavoidable impurities and Ni, the nonmagnetic high-hardness alloy being subjected to cold or warm plastic working and then ageing treatment, and a method for producing the nonmagnetic high-hardness alloy.

Abstract: An exhaust valve for automobile engines, which is durable at such a high temperature as 900° C., and exhibits high fatigue strength and high oxidation resistance is disclosed. The exhaust valve is made of a Ni-based alloy consisting essentially of, by weight %. C: 0.01-0.15%, Si: up to 2.0%, Mn: up to 1.0%, P: up to 0.02%, S: up to 0.01%, Co: 0.1-15%, Cr: 15-25%, one or two of Mo: 0.1-10% and W: 0.1-5% in such amount that Mo+½ W; 3-10%, Al: 1.0-3.0%, Ti: 2.0-3.5%, provided that, by atomic %, Al+Ti: 6.3-8.5% and Ti/Al ratio: 0.4-0.8, and further, by weight %, B: 0.001-0.01%, Fe: up to 3%, and the balance of Ni and inevitable impurities by hot forging to give the form of an exhaust valve and subjecting to solid solution at 1000-1200° C. and aging at 700-950° C.