Abstract: A nickel alloy having superior surface properties by controlling the composition of non-metallic inclusions that affect surface properties, and a method for producing the same. A nickel alloy includes: all by mass %, Ni: 99.0% or more, C: 0.020% or less, Si: 0.01 to 0.3%, Mn: 0.3% or less, S: 0.010% or less, Cu: 0.2% or less, Al: 0.001 to 0.1%, Fe: 0.4% or less, O: 0.0001 to 0.0050% or less, Mg: 0.001 to 0.030%, Ca: 0.0001 to 0.0050%, B: 0.0001 to 0.01%, and the balance of inevitable impurities; the alloy including non-metallic inclusions, in which the non-metallic inclusions include one or more of MgO, CaO, CaO—Al2O3-based oxides, CaO—SiO2-based oxides, CaO—MgO-based oxides, and MgO·Al2O3, the MgO·Al2O3 has a number ratio of number 50% or less with respect to all oxide-based, non-metallic inclusions.

Abstract: A highly corrosion-resistant austenite stainless steel that, even when exposed to temperatures in a range in which a ? phase is precipitated and corrosion resistance varies greatly, the stainless steel remains corrosion resistant, the steel consisting of, in mass %: C: 0.005 to 0.030%, Si: 0.05 to 0.30%, Mn: 0.05 to 0.40%, P: 0.005 to 0.050%, S: 0.0001 to 0.0010%, Ni: 22.0 to 32.0%, Cr: 19.0 to 28.0%, Mo: 5.0 to 7.0%, N: 0.18 to 0.25%, Al: 0.005 to 0.100%, Cu: 0.05 to 0.50%, W: not more than 0.05%, Sn: 0.0005 to 0.0150%, Co: 0.030 to 0.300%, B: 0.0005 to 0.0050%, Fe as a remainder and inevitable impurities, in which the stainless steel satisfies the following formula (1), an area ratio of ? phase is not more than 1%, and CPT based on ASTM G48 Method C as corrosion resistance property is not less than 60° C. 0.05?10[% B]+2[% P]+6[% Sn]+0.03[% Si]?0.

Abstract: Fe—Ni—Cr alloy contains, in mass, from 0.001% to 0.050% of C, from 0.18% to 1.00% of Si, from 0.20% to 0.80% of Mn, 0.030% or less of P, 0.0001% to 0.0020% of S, from 12% to 21% of Ni, from 18% to 24% of Cr, from 0.20% to 1.50% of Mo, 0.30% or less of Cu, from 0.10% to 0.70% of Al, from 0.10% to 0.70% of Ti, from 0.002% to 0.015% of N, from 0.0001% to 0.0010% of B, from 0.0002% to 0.0030% of O, 0.002% or less of Ca, and from 0.0010% to 0.0150% of REM in total, said REM being composed of one or more elements selected from among La, Ce and Y, with the balance being made up of Fe and unavoidable impurities, and which satisfies formulae 1 and 2. Formula 1: 0.575xNi+1.25xCr+3.43xMo-39xP-5.3xAl-641xREM-1018xO?20.0 Formula 2: 1.5xMn+41.3xSi+1469xS-1.67xAl-1.34xTi-150xO-620xREM?5.0.

Abstract: A highly corrosion-resistant Ni—Cr Mo—N alloy including in weight %, Ni: 22.0% or more, Cr: 22.0% or more, Mo: 5.0% or more, N: 0.180% or more, Si, Al, Mn, Fe as a remainder, and inevitable impurities, wherein the composition satisfies the following Formulas (1) to (3), and an area ratio of a sigma phase in a cross-sectional structure measured by EBSD after holding at 950° C. for 30 minutes is 1.0% or less Cr+3.3×Mo+16×N?43.0??(1) 7.3×Mo—Ni?21.0??(2-1) 1.3×?5.7??(2-2) 1.6×Si+0.99×Mn+2.2×Al?0.95??(3).

Abstract: A Ni—Cr—Mo—Nb alloy consists of, in mass %, C: not more than 0.020%, Si: 0.02 to 1.0%, Mn: 0.02 to 1.0%, P: not more than 0.03%, S: not more than 0.005%, Cr: 18.0 to 24.0%, Mo: 8.0 to 10.0%, Al: 0.005 to 0.4%, Ti: 0.1 to 1.0%, Fe: not more than 5.0%, Nb: 2.5 to 5.0%, N: 0.002 to 0.02%, and at least one of W: 0.02 to 0.3% and V: 0.02 to 0.3%, and Ni as a remainder and inevitable impurities, in which an freely selected cross section of alloy, sum of number of particles of NbC carbide and (Ti, Nb)N nitride is 100 to 1000 particles/mm2, number of particles of the NbC carbide is not more than 40 particles/mm2, and number of particles of the (Ti, Nb)N nitride is 100 to 1000 particles/mm2.

Abstract: A duplex stainless steel has reduced precipitation risks of Al nitride and Cr nitride which are undesirable precipitates, and has superior low temperature toughness. The duplex stainless steel has in mass %, indicated as “%”, C: 0.001 to 0.030%, Si: 0.05 to 0.5%, S: not more than 0.002%, Ni: 6 to 7.5%, Cr: 23 to 26%, Mo: 2 to 4.0%, N: 0.20 to 0.40%, Al: 0.005 to 0.03%, Mn: 0.05 to 0.3%, B: 0.0001 to 0.0050% and Fe, and the remainder being inevitable impurities. The duplex stainless steel has an impact value of not less than 87.5 J/cm2 at ?46±2° C. as defined in Japanese Industrial Standards Z2242.

Abstract: Alloy compositions, structures, and production methods for an appropriate slit cut surface shape improve productivity by increasing welding speed and stabilizing quality during high speed welding in Ti-containing Fe—Ni—Cr alloy production. The Ti-containing Fe—Ni—Cr alloy contains, hereinafter in weight %, C: 0.001 to 0.03%, Si: 0.05 to 1.25%, Mn: 0.10 to 2.00%, P: 0.001 to 0.030%, S: 0.0001 to 0.0030%, Ni: 15 to 50%, Cr: 17 to 25%, Al: 0.10 to 0.80%, Ti: 0.10 to 1.5%, N: 0.003 to 0.025%, 0: 0.0002 to 0.007%, Fe as a remainder, and inevitable impurities, and when the number and size of titanium nitrides contained in material are evaluated in a freely selected field of view of 5 mm2, the titanium nitrides having sizes of not more than 15 ?m are not less than 99.3% of total of the titanium nitrides.

Abstract: Ti, N, Al, Mg, and Ca concentrations are controlled in order to prevent aggregation of TiN inclusions. Furthermore, not only is a Fe—Cr—Ni alloy having superior surface property provided, but also a method is proposed in which the Fe—Cr—Ni alloy is produced at low cost using commonly used equipment. The Fe—Cr—Ni alloy includes C?0.05%, Si: 0.1 to 0.8%, Mn: 0.2 to 0.8%, P?0.03%, S?0.001%, Ni:16 to 35%, Cr: 18 to 25%, Al: 0.2 to 0.4%, Ti: 0.25 to 0.4%, N?0.016%, Mg: 0.0015 to 0.008%, Ca?0.005%, O: 0.0002 to 0.005%, freely selected Mo: 0.5 to 2.5% in mass % and Fe and inevitable impurities as the remainder, wherein Ti and N satisfy % N×% Ti?0.0045 and the number of TiN inclusions not smaller than 5 ?m is 20 to 200 pieces/cm2 at a freely selected cross section.

Abstract: Provided is an Fe—Ni—Cr alloy that has excellent surface characteristics and enables formation of a blackened coating having excellent blackening characteristics and peeling resistance. The Fe—Ni—Cr alloy has a chemical composition containing, by mass %, C, Si, Mn, P, S, Cr, Ni, Mo, Co, Cu, N, Ti, Al, O, and H, the balance being Fe and inevitable impurities, and satisfying formulae (1) to (4): (1) T1=11×[% N]+0.1; (2) T2=?39×[% N]?1.0; (3) A1=7.5×[% N]+0.1; (4) A2=?42.5×[% N]+1.0, where [% M] represents content (mass %) of element M in the alloy, and T1, T2, A1, and A2 satisfy relationships T1<[% Ti]<T2 and A1<[% A1]<A2.

Abstract: Ti, N, Al, Mg, and Ca concentrations are controlled in order to prevent aggregation of TiN inclusions. Furthermore, not only is a Fe—Cr—Ni alloy having superior surface property provided, but also a method is proposed in which the Fe—Cr—Ni alloy is produced at low cost using commonly used equipment. The Fe—Cr—Ni alloy includes C?0.05%, Si: 0.1 to 0.8%, Mn: 0.2 to 0.8%, P?0.03%, S?0.001%, Ni:16 to 35%, Cr: 18 to 25%, Al: 0.2 to 0.4%, Ti: 0.25 to 0.4%, N?0.016%, Mg: 0.0015 to 0.008%, Ca?0.005%, O: 0.0002 to 0.005%, freely selected Mo: 0.5 to 2.5% in mass % and Fe and inevitable impurities as the remainder, wherein Ti and N satisfy % N×% Ti?0.0045 and the number of TiN inclusions not smaller than 5 ?m is 20 to 200 pieces/cm2 at a freely selected cross section.

Abstract: A duplex stainless steel has reduced precipitation risks of Al nitride and Cr nitride which are undesirable precipitates, and has superior low temperature toughness. The duplex stainless steel has in mass %, indicated as “%”, C: 0.001 to 0.030%, Si: 0.05 to 0.5%, S: not more than 0.002%, Ni: 6 to 7.5%, Cr: 23 to 26%, Mo: 2 to 4.0%, N: 0.20 to 0.40%, Al: 0.005 to 0.03%, Mn: 0.05 to 0.3%, B: 0.0001 to 0.0050% and Fe, and the remainder being inevitable impurities. The duplex stainless steel has an impact value of not less than 87.5 J/cm2 at ?46±2° C. as defined in Japanese Industrial Standards Z2242.

Abstract: The Ni-based alloy exhibits superior grain boundary corrosion resistance including C: 0.005 to 0.03 mass %, Si: 0.02 to 1 mass %, Mn: 0.02 to 1 mass %, P: not more than 0.03 mass %, S: not more than 0.005 mass %, Cr: 18 to 24 mass %, Mo: 8 to 10 mass %, Nb: 2.5 to 5.0 mass %, Al: 0.05 to 0.4 mass %, Ti: not more than 1 mass %, Fe: not more than 5 mass %, N: not more than 0.02 mass %, and Ni as a remainder and inevitable impurities. The C concentration range, the ratio of (Nb, Ti) C carbides to all carbides is not less than 90%, and the number of (Nb, Ti) C carbides satisfies the following formula: ?30×T+37220=<number of (Nb, Ti) C carbides (number/mm2)=<?7.7×T2+15700×T?7866000 under a condition of 2000×% C+890=<T(temperature ° C.)=<1150.

Abstract: Provided is an Fe—Ni—Cr alloy that has excellent surface characteristics and enables formation of a blackened coating having excellent blackening characteristics and peeling resistance. The Fe—Ni—Cr alloy has a chemical composition containing, by mass %, C, Si, Mn, P, S, Cr, Ni, Mo, Co, Cu, N, Ti, Al, O, and H, the balance being Fe and inevitable impurities, and satisfying formulae (1) to (4): (1) T1=11×[% N]+0.1; (2) T2=?39×[% N]?1.0; (3) A1=7.5×[% N]+0.1; (4) A2=?42.5×[% N]+1.0, where [% M] represents content (mass %) of element M in the alloy, and T1, T2, A1, and A2 satisfy relationships T1<[% Ti]<T2 and A1<[% A1]<A2.

Abstract: Fe—Cr—Ni—Mo alloy having superior surface properties and a method for producing the same using a commonly used apparatus at low cost. The Fe—Cr—Ni—Mo alloy has (% indicates mass %): C: ?0.03%, Si: 0.15 to 0.5%, Mn: 0.1 to 1%, P: ?0.03%, S: ?0.002%, Ni: 20 to 32%, Cr: 20 to 26%, Mo: 0.5 to 2.5%, Al: 0.1 to 0.5%, Ti: 0.1 to 0.5%, Mg: 0.0002 to 0.01%, Ca: 0.0002 to 0.01%, N: ?0.02%, O: 0.0001 to 0.01%, freely contained components of Co: 0.05 to 2% and Cu: 0.01 to 0.5%, Fe as a remainder, and inevitable impurities, wherein MgO, MgO.Al2O3 spinel type, and CaO—Al2O3—MgO type are contained as oxide type non-metallic inclusions, ratio of number of MgO.Al2O3 spinel type to all oxide type non-metallic inclusions is ?50%, and CaO—Al2O3—MgO type contains CaO: 30 to 70%, Al2O3: 5 to 60%, MgO: 1 to 30%, SiO2: ?8%, and TiO2: ?10%.

Abstract: The Ni-based alloy exhibits superior grain boundary corrosion resistance including C: 0.005 to 0.03 mass %, Si: 0.02 to 1 mass %, Mn: 0.02 to 1 mass %, P: not more than 0.03 mass %, S: not more than 0.005 mass %, Cr: 18 to 24 mass %, Mo: 8 to 10 mass %, Nb: 2.5 to 5.0 mass %, Al: 0.05 to 0.4 mass %, Ti: not more than 1 mass %, Fe: not more than 5 mass %, N: not more than 0.02 mass %, and Ni as a remainder and inevitable impurities. The C concentration range, the ratio of (Nb, Ti) C carbides to all carbides is not less than 90%, and the number of (Nb, Ti) C carbides satisfies the following formula: ?30×T+37220=<number of (Nb, Ti) C carbides (number/mm2)=<?7.7×T2+15700×T?7866000 under a condition of 2000×% C+890=<T(temperature ° C.)=<1150.

Abstract: An austenitic Fe—Ni—Cr alloy comprises C: 0.005˜0.03 mass %, Si: 0.17˜1.0 mass %, Mn: not more than 2.0 mass %, P: not more than 0.030 mass %, S: not more than 0.0015 mass %, Cr: 18˜28 mass %, Ni: 21.5˜32 mass %, Mo: 0.10˜2.8 mass %, Co: 0.05˜2.0 mass %, Cu: less than 0.25 mass %, N: not more than 0.018 mass %, Al: 0.10˜1.0 mass %, Ti: 0.10˜1.0 mass %, Zr: 0.01˜0.5 mass %, and the balance being Fe and inevitable impurities; wherein Cr, Mo, N and Cu satisfy PRE=Cr+3.3×Mo+16×N?20.0 and PREH=411-13.2×Cr-5.8×Mo+0.1×Mo2+1.2×Cu?145.0 and wherein Al, Ti, and Zr satisfy 0.5?Al+Ti+1.5×Zr?1.5, and has an excellent corrosion resistance in air or under a wet environment even at a surface state having an oxide film formed by an intermediate heat treatment.

Abstract: Fe—Cr—Ni—Mo alloy having superior surface properties and a method for producing the same using a commonly used apparatus at low cost. The Fe—Cr—Ni—Mo alloy has (% indicates mass %): C: ?0.03%, Si: 0.15 to 0.5%, Mn: 0.1 to 1%, P: ?0.03%, S: ?0.002%, Ni: 20 to 32%, Cr: 20 to 26%, Mo: 0.5 to 2.5%, Al: 0.1 to 0.5%, Ti: 0.1 to 0.5%, Mg: 0.0002 to 0.01%, Ca: 0.0002 to 0.01%, N: ?0.02%, O: 0.0001 to 0.01%, freely contained components of Co: 0.05 to 2% and Cu: 0.01 to 0.5%, Fe as a remainder, and inevitable impurities, wherein MgO, MgO.Al2O3 spinel type, and CaO—Al2O3—MgO type are contained as oxide type non-metallic inclusions, ratio of number of MgO.Al2O3 spinel type to all oxide type non-metallic inclusions is ?50%, and CaO—Al2O3—MgO type contains CaO: 30 to 70%, Al2O3: 5 to 60%, MgO: 1 to 30%, SiO2: ?8%, and TiO2: ?10%.

Abstract: High-Mn austenitic stainless steels having a chemical composition comprising C: 0.02-0.12 mass %, Si: 0.05-1.5 mass %, Mn: 10.0-22.0 mass %, S: not more than 0.0028 mass %, Ni: 4.0-12.0 mass %, Cr: 14.0-25.0 mass % and N: 0.07-0.17 mass % with the balance being Fe and inevitable impurities, provided that these components are contained so that ? cal represented by the following equation is not more than 5.5%: ? cal (mass %)=(Cr+0.48Si)?(Ni+0.11Mn?0.0101Mn2+26.4C+20.1N)?4.7, wherein each element symbol in the equation is a content of the respective element (mass %), and having a magnetic permeability of not more than 1.003 under a magnetic field of 200 kA/m.

Abstract: A boron-containing stainless steel having excellent hot workability and weldability and a good surface quality is proposed and is a boron-containing stainless steel comprising C: 0.001-0.15 mass %, Si: 0.1-2 mass %, Mn: 0.1-2 mass %, Ni: 5-25 mass %, Cr: 11-27 mass %, B: 0.05-2.5 mass %, Al: 0.005-0.2 mass %, O: 0.0001-0.01 mass %, N: 0.001-0.1 mass %, S: not more than 0.005 mass %, one or both of Mg: 0.0001-0.005 mass % and Ca: 0.0001-0.005 mass % and the remainder being Fe and inevitable impurities provided that a part of Si, Al, Mg, Ca and S is included as a non-metallic inclusion made of sulfide and/or oxysulfide.

Abstract: An austenitic Fe—Ni—Cr alloy comprises C: 0.005˜0.03 mass %, Si: 0.17˜4.0 mass %, Mn: not more than 2.0 mass %, P: not more than 0.030 mass %, S: not more than 0.0015 mass %, Cr: 18˜28 mass %, Ni: 21.5˜32 mass %, Mo: 0.10˜2.8 mass %, Co: 0.05˜2.0 mass %, Cu: less than 0.25 mass %, N: not more than 0.018 mass %, Al: 0.10˜4.0 mass %, Ti: 0.10˜1.0 mass %, Zr: 0.01˜0.5 mass %, and the balance being Fe and inevitable impurities; wherein Cr, Mo, N and Cu satisfy PRE=Cr+3.3×Mo+16×N?20.0 and PREH=411-13.2×Cr-5.8×Mo+0.1×Mo2+1.2×Cu?145.0 and wherein Al, Ti, and Zr satisfy 0.5?Al+Ti+1.5×Zr?1.5, and has an excellent corrosion resistance in air or under a wet environment even at a surface state having an oxide film formed by an intermediate heat treatment.