Abstract: A ferritic stainless steel suited for use as a member for heat exchangers to be brazed with Ni-based filler metal or Cu-based filler metal, comprising, on the basis of mass percent, C: 0.03% or less, Si: 3% or less, Mn: 2% or less, P: 0.05% or less, S: 0.03% or less, Cr: from 11 to 30%, Nb: from 0.15 to 0.8%, and N: 0.03% or less, wherein the balance is composed of Fe and incidental impurities, and wherein a value A determined by the following equation is 0.10 or greater: A=Nb?(C×92.9/12+N×92.9/14).

Abstract: A hot water tank having, on the inner surface thereof, a back bead formed by TIG-welding with no back gas sealing of steel members to each other having a composition comprising, % by mass, C: at most 0.025%, Si: at most 1%, Mn: at most 1%, P: at most 0.045%, S: at most 0.01%, Ni: from 0.1 to 1%, Cr: from more than 21 to 25%, Mo: from 0.1 to 2%, Al: from 0.02 to 0.3%, N: at most 0.025%, and Cu: from 0 to 1%, and containing at least one of Ti: from 0.05 to 0.4% and Nb: from 0.05 to 0.5%, with the balance of Fe and inevitable impurities, wherein the Cr concentration in the steel basis material in the area having oxide scale soluble in an aqueous chloride solution, as formed therein in the heat-affected zone on the welded back side thereof, is at least 16% by mass in the depth region of at least 10 nm from the steel basis material/oxide scale interface.

Abstract: Disclosed is a ferritic stainless steel for hot-water tanks with welded structure, comprising, in terms of % by mass, at most 0.02% of C, from 0.01 to 0.30% of Si, at most 1% of Mn, at most 0.04% of P, at most 0.03% of S, from more than 21 to 26% of Cr, at most 2% of Mo, from 0.05 to 0.6% of Nb, from 0.05 to 0.4% of Ti, at most 0.025% of N, and from 0.02 to 0.3% of Al, and optionally containing at least one of at most 2%, preferably from 0.1 to 2% of Ni and at most 1%, preferably from 0.1 to 1% of Cu, with a balance of Fe and inevitable impurities.

Abstract: A ferritic stainless steel sheet has a composition of C up to 0.02 mass %, Si up to 0.8 mass %, Mn up to 1.5 mass %, P up to 0.050 mass %, S up to 0.01 mass %, 8.0-35.0 mass % of Cr, N up to 0.05 mass %, 0.05-0.40 mass % of Ti and 0.10-0.50 mass % of Nb with a product of (% Ti % N) less than 0.005. Precipitates of 0.15 ?m or more in particle size except TiN are distributed in a steel matrix at a rate of 5000-50000/mm2. The steel sheet is manufactured by hot-rolling a slab at a finish-temperature of 800° C. or lower, annealing the hot-rolled steel sheet at 450-1080° C., cold-rolling the hot-rolled steel sheet in accompaniment with intermediate-annealing at a temperature within a range of from (a recrystallization-finishing temperature ?100° C.) to (a recrystallization-finishing temperature) and then finish-annealing the cold-rolled steel sheet at 1080° C. or lower.

Abstract: When a metastable austenitic stainless steel strip with a value Md(N), which is calculated from a composition, of 20–100 is ring-rolled to a steel belt, the relationship of ?0.3913T+0.5650Md(N)+60.46??65.87 is established among a material temperature T, an equivalent strain ? and the value Md(N). Due to the controlled rolling, a stainless steel belt for a continuously variable transmission is bestowed with fatigue properties similar or superior to those of a 18%-Ni maraging steel belt. The value Md(N) is defined by the equation of Md(N)=580?520C?2Si?16Mn?16Cr?23Ni?300N?10Mo, and the equivalent strain ? is defined by the equation of ?=?{square root over (4(1n(1?R))2/3)} (R: reduction). Furthermore, the steel belt is stabilized in its quality and profile by confining a variation ?T of the material temperature T within a range of ±6.4° C.

Abstract: A ferritic stainless steel sheet has a composition of C up to 0.02 mass %, Si up to 0.8 mass %, Mn up to 1.5 mass %, P up to 0.050 mass %, S up to 0.01 mass %, 8.0-35.0 mass % of Cr, N up to 0.05 mass %, 0.05-0.40 mass % of Ti and 0.10-0.50 mass % of Nb with a product of (% Ti×% N) less than 0.005. Precipitates of 0.15 &mgr;m or more in particle size except TiN are distributed in a steel matrix at a rate of 5000-50000/mm2. The steel sheet is manufactured by hot-rolling a slab at a finish-temperature of 800° C. or lower, annealing the hot-rolled steel sheet at 450-1080° C., cold-rolling the hot-rolled steel sheet in accompaniment with intermediate-annealing at a temperature within a range of from (a recrystallization-finishing temperature −100° C.) to (a recrystallization-finishing temperature) and then finish-annealing the cold-rolled steel sheet at 1080° C. or lower.

Abstract: A fuel tank and a fuel-filler tube, which maintain excellent corrosion-resistance over a long term even in a severely corrosive atmosphere, is made of a ferritic stainless steel sheet good of formability. The steel sheet, which has elongation of 30% or more after fracture by a uniaxial tensile test and minimum Lankford value (value-rmin) of 1.3 or more, is formed to a product shape, and paint is cathodically electrodeposited on a surface of the formed stainless steel sheet. The stainless steel sheet may be one coated with an Al or Zn plating layer. When the fuel tank or fuel-filler tube is fabricated by welding, Zn-rich paint is preferably applied to a welded part in prior to cathodic electrodeposition coating.

Abstract: A high-strength dual-phase stainless steel strip has a chemical composition consisting of 0.04-0.15 mass % C, 10.0-20.0 mass % Cr, 0.5-4.0 mass % Ni and the balance being Fe except inevitable impurities, and a metallurgical structure composed of 20-85 vol. % martensite grains and the balance ferrite grains with prior austenite grains controlled to 10 &mgr;m or less in size. The stainless steel strip is conditioned to hardness of HV 300 or more. Transformation strains are uniformly distributed in a steel matrix during martensitic transformation, so that the steel strip is formed and straightened to a belt shape without Lüders band. Consequently, steel belts with fine external appearance are manufactured from the stainless steel strip.

Abstract: A ferritic stainless steel sheet, which is press-formed to a product shape without such dimensional defects as spring-back or torsion, has an alloying composition consisting of C up to 0.10%, Si up to 1.0%, Mn up to 1.0%, P up to 0.050%, S up to 0.020%, Ni up to 2.0%, 8.0-22.0% of Cr, N up to 0.05%, optionally one or more of Al up to 0.10%, Mo up to 1.0%, Cu up to 1.0%, 0.010-0.50% of Ti, 0.010-0.50% of Nb, 0.010-0.30% of V, 0.010-0.30% of Zr and 0.0010-0.0100% of B, and the balance being essentially Fe with the provision that a value-FM defined by the formula (1) is adjusted to 0 or less. Its mechanical properties are controlled to a plane anisotropic degree (rmax−rmin) of Lankford value (r) ≦0.80 and an anisotropic degree (&sgr;max−&sgr;min) of 0.2%-yield strength ≦20 N/mm2. The stainless steel sheet is manufactured by hot-rolling a stainless steel having the specified composition and then batch-annealing the hot-rolled steel sheet 1-24 hours at 700-800° C.

Abstract: A high-strength austenitic stainless steel strip exhibiting excellent flatness with Vickers hardness of 400 or more has the composition comprising: C up to 0.20 mass %, Si up to 4.0 mass %, Mn up to 5.0 mass %, 4.0-12.0 mass % Ni, 12.0-20.0 mass % Cr, Mo up to 5.0 mass %, N up to 0.15 mass % and the balance being Fe except inevitable impurities having a value Md(N) in a range of 0-125 defined by the formula Md(N)=580-520C-2Si-16Mn-16Cr-23Ni-26Cu-300N-10Mo. The material has a dual-phase structure of austenite and martensite involving a reverse-transformed austenite at a ratio of 3 vol. % or more. The material is manufactured by solution-heating a steel strip having the above composition, cold-rolling the steel strip to generate a deformation-induced martensite, and then re-heating at 500-700° C. to induce a phase reversion from martensite to at least 3 vol. % austenite. The reversion effectively flattens the steel strip.

Abstract: When a metastable austenitic stainless steel strip with a value Md(N), which is calculated from a composition, of 20-100 is ring-rolled to a steel belt, the relationship of −0.3913T+0.5650Md(N)+60.46&egr;≧65.87 is established among a material temperature T, an equivalent strain &egr; and the value Md(N). Due to the controlled rolling, a stainless steel belt for a continuously variable transmission is bestowed with fatigue properties similar or superior to those of a 18%-Ni maraging steel belt. The value Md(N) is defined by the equation of Md(N)=580−520C−2Si−16Mn−16Cr−23Ni−300N−10Mo, and the equivalent strain &egr; is defined by the equation of E={square root}{square root over (4(1n(1−R))2/3)} (R: reduction). Furthermore, the steel belt is stabilized in its quality and profile by confining a variation &Dgr;T of the material temperature T within a range of ±6.4° C.

Abstract: A high-strength, high-toughness martensitic stainless steel sheet has a chemical composition comprising, in mass percent, more than 0.03 to 0.15% of C, 0.2-2.0% of Si, not more than 1.0% of Mn, not more than 0.06% of P, not more than 0.006% of S, 2.0-5.0% of Ni, 14.0-17.0% of Cr, more than 0.03 to 0.10% of N, 0.0010-0.0070% of B, and the balance of Fe and unavoidable impurities and has an A value of not less than −1.8, where A value=30(C+N)−1.5Si+0.5Mn+Ni−1.3Cr+11.8. The suitability of the steel sheet as a gasket material is enhanced by producing it to include not less than 85 vol % of martensite phase and to have a spring bending elastic limit Kb0.1 after application of tensile strain of 0.1% of not less than 700 N/mm2. Edge cracking during cold rolling is inhibited by conducting cold rolling after subjecting the hot-rolled sheet to 600-800° C.×10 hr or less intermediate annealing to impart a steel hardness of not greater than Hv 380.

Abstract: A fuel tank and a fuel-filler tube, which maintain excellent corrosion-resistance over a long term even in a severely corrosive atmosphere, is made of a ferritic stainless steel sheet good of formability. The steel sheet, which has elongation of 30% or more after fracture by a uniaxial tensile test and minimum Lankford value (value-rmin) of 1.3 or more, is formed to a product shape, and paint is cathodically electrodeposited on a surface of the formed stainless steel sheet. The stainless steel sheet may be one coated with an Al or Zn plating layer. When the fuel tank or fuel-filler tube is fabricated by welding, Zn-rich paint is preferably applied to a welded part in prior to cathodic electrodeposition coating.

Abstract: A high-strength, high-toughness martensitic stainless steel sheet has a chemical composition comprising, in, mass percent, more than 0.03 to 0.15% of C, 0.2-2.0% of Si, not more than 1.0% of Mn, not more than 0.06% of P, not more than 0.006% of S, 2.0-5.0% of Ni, 14.0-17.0% of Cr, more than 0.03 to 0.10% of N, 0.0010-0.0070% of B, and the balance of Fe and unavoidable impurities and has an A value of not less than −1.8, where A value=30(C+N)−1.5Si+0.5Mn+Ni−1.3Cr+11.8. The suitability of the steel sheet as a gasket material is enhanced by producing it to include not less than 85 vol % of martensite phase and to have a spring bending elastic limit Kb0.1 after application of tensile strain of 0.1% of not less than 700 N/mm2. Edge cracking during cold rolling is inhibited by conducting cold rolling after subjecting the hot-rolled sheet to 600-800° C.×10 hr or less intermediate annealing to impart a steel hardness of not greater than Hv 380.

Abstract: A high-strength, high-toughness martensitic stainless steel sheet has a chemical composition comprising, in mass percent, more than 0.03 to 0.15% of C, 0.2-2.0% of Si, not more than 1.0% of Mn, not more than 0.06% of P, not more than 0.006% of S, 2.0-5.0% of Ni, 14.0-17.0% of Cr, more than 0.03 to 0.10% of N, 0.0010-0.0070% of B, and the balance of Fe and unavoidable impurities and has an A value of not less than −1.8, where A value=30(C+N)−1.5Si+0.5Mn+Ni−1.3Cr+11.8. The suitability of the steel sheet as a gasket material is enhanced by producing it to include not less than 85 vol % of martensite phase and to have a spring bending elastic limit Kb0.1 after application of tensile strain of 0.1% of not less than 700 N/mm2. Edge cracking during cold rolling is inhibited by conducting cold rolling after subjecting the hot-rolled sheet to 600-800 ° C.×10 hr or less intermediate annealing to impart a steel hardness of not greater than Hv 380.

Abstract: An ultra-high strength metastable austenitic stainless steel exhibiting a tensile strength of not less than 2200 N/mm2 has a chemical composition comprising, in mass %, not more than 0.15 % of C, more than 1.0 to 6.0 % of Si, not more than 5.0 % of Mn, 4.0-10.0 % of Ni, 12.0-18.0 % of Cr, not more than 3.5 % of Cu, not more than 5.0 % of Mo, not more than 0.02 % of N, 0.1-0.5 % of Ti, optionally one or both of not more than 0.5 % of V and not more than 0.5 % of Nb, and the balance of Fe and unavoidable impurities, satisfies Si+Mo≧3.5 %, has a value of Md(N) defined by the equation Md(N)=580-520C-2Si-16Mn-16Cr-23Ni-300N-26Cu-10Mo of 20-140, exhibits a cold worked multiphase texture composed of 50-95 vol % of martensite phase and the remainder substantially of austenite phase, and has Mo-system precipitates and Ti-system precipitates distributed in the martensite phase.

Abstract: A high-strength austenitic stainless steel strip excellent in flatness of shape with Vickers hardness of 400 or more is newly proposed, which has the composition consisting of C up to 0.20 mass %, Si up to 4.0 mass %, Mn up to 5.0 mass %, 4.0-12.0 mass % Ni, 12.0-20.0 mass % Cr, Mo up to 5.0 mass %, N up to 0.15 mass % and the balance being Fe except inevitable impurities under the condition that a value Md(N) defined by the formula (1) is in a range of 0-125. It has a dual-phase structure of austenite and martensite involving reverse-transformed austenite at a ratio of 3 vol. % or more. It is manufactured by solution-heating a steel strip having the composition, cold-rolling the steel strip to generate deformation-induced martensite, and then re-heating at 500-700° C. to induce reversion. The reversion effectively flattens a shape of the steel strip.

Abstract: A steel sheet for disk brake with improved anti-warp property has a chemical composition comprising, in mass percent, 0.05-0.15% of C, not more than 1.0% of Si, not more than 2.0% of Mn, not more than 1.0% of Ni, 9.0-15.0% of Cr, 0.5-4.0% of Cu, 0.10-2.0% of Mo, not more than 0.10% of N, 0.05-1.

Abstract: A high-strength, high-toughness martensitic stainless steel sheet has a chemical composition comprising, in mass percent, more than 0.03 to 0.15% of C, 0.2-2.0% of Si, not more than 1.0% of Mn, not more than 0.06% of P, not more than 0.006% of S, 2.0-5.0% of Ni, 14.0-17.0% of Cr, more than 0.03 to 0.10% of N, 0.0010-0.0070% of B, and the balance of Fe and unavoidable impurities and has an A value of not less than −1.8, where A value=30(C+N)−1.5Si+0.5Mn+Ni−1.3Cr+11.8. The suitability of the steel sheet as a gasket material is enhanced by producing it to include not less than 85 vol % of martensite phase and to have a spring bending elastic limit Kb0.1 after application of tensile strain of 0.1% of not less than 700 N/mm2. Edge cracking during cold rolling is inhibited by conducting cold rolling after subjecting the hot-rolled sheet to 600-800 ° C.×10 hr or less intermediate annealing to impart a steel hardness of not greater than Hv 380.