Abstract: A ferritic or martensitic stainless steel has the structure that Cu-enriched particles with concentration of C not less than 0.1 mass % or concentration of Sn and/or In not less than 10 mass % were dispersed in a matrix. Precipitation and dispersion of Cu-enriched particles is realized by aging the stainless steel at 500-900° C. for 1 hour or longer on any stage after a hot-rolling step until a forming step to a final product. The ferritic stainless steel contains 0.01-1.0% C, Si up to 1.0%, Mn up to 1.0%, 15-30% Cr, Ni up to 6.0% and 0.5-6.0% Cu. The martensitic stainless steel contains 0.01-0.5% C, Si up to 1.0%, Mn up to 1.0%, 10-15% Cr, Ni up to 6.0% and 0.5-6.0% Cu. Since Cu-enriched particles are dispersed for improvement of machinability instead of addition of S, Pb, Bi or Se, the stainless steel is machined to an objective shape without any harmful influence on workability, corrosion-resistance and the environment.

Abstract: A fuel tank for a motor vehicle is fabricated from an austenitic stainless steel sheet having elongation of 50% or more after fracture by a uniaxial stretching test with a work-hardening coefficient of 4000N/mm2 or a ferritic stainless steel sheet having elongation of 30% or more after fracture with Lankford value of 1.3 or more. The stainless steel sheets are reformed to a complicated shape of a fuel tank without work flaws such as cracks or break-down. Excellent corrosion-resistance of stainless steel itself is maintained in the fabricated fuel tank. Consequently, the proposed fuel tank is used without diffusion of gasoline to the open air over a long term.

Abstract: A new soft stainless steel sheet has an austenite-stability index Md30 controlled in a range of −120 to −10 and a stacking fault formability index SFI controlled not less than 30, and involves precipitates whose Cu concentration is controlled not more than 1.0%, so as to maintain concentration of dissolved Cu at 1-5%. The stainless steel sheet preferably contains up to 0.06%(C+N), up to 2.0% Si, up to 5% Mn, 15-20% Cr, 5-9% Ni, 1.0-4.0% Cu, up to 0.003% Al, up to 0.005% S, and optionally one or more of up to 0.5% Ti, up to 0.5% Nb, up to 0.5% Zr, up to 0.5% V, up to 3.0% Mo, up to 0.03% B, up to 0.02% REM (rare earth metals) and up to 0.03% Ca. The stainless steel sheet can be plastically deformed to an objective shape without any cracks even at a part heavily-worked part by multi-stage deep drawing or compression deforming. Md30(° C.)=551−462(C+N)−9.2Si−8.1Mn−29(Ni+Cu)−13.7Cr−18.5Mo SFI(mJ/m2)=2.2Ni+6Cu−1.

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 stainless steel suitable for use with a needle detector, that has a magnetic permeability of 1.005 or less in a magnetic field of 1 kOe, and a magnetization of 550 memu/g or less in a magnetic field of 18 kOe. The steel comprises, in mass %, 0.01 to 0.15% of C, 0.1 to 5% of Si, 1 to 10% of Mn, 8 to 25% of Ni, 14 to 30% of Cr, 0.01 to 0.25% of N, and the remainder Fe and impurities, wherein an Ni equivalent, which is defined as Ni equivalent=Ni+0.6Mn+9.69(C+N)+0.18Cr−0.11Si2, has a value of 19 or more, and may further contain at least one selected from among a) 0.5 to 3% of Cu, b) 0.05 to 0.5% of at least one element selected from Nb, W and V, and c) 0.1 to 2% of Mo.

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 new soft stainless steel sheet has an austenite-stability index Md30 controlled in a range of −120 to −10 and a stacking fault formability index SFI controlled not less than 30, and involves precipitates whose Cu concentration is controlled not more than 1.0%, so as to maintain concentration of dissolved Cu at 1-5%. The stainless steel sheet preferably contains up to 0.06%(C+N), up to 2.0% Si, up to 5% Mn, 15-20% Cr, 5-9% Ni, 1.0-4.0% Cu, up to 0.003% Al, up to 0.005% S, and optionally one or more of up to 0.5% Y, up to 0.5% Nb, up to 0.5% Zr, up to 0.5% V, up to 3.0% Mo, up to 0.03% B, up to 0.02% REM (rare earth metals) and up to 0.03% Ca. The stainless steel sheet can be plastically deformed to an objective shape without any cracks even at a part heavily-worked part by multi-stage deep drawing or compression deforming.

Abstract: An austenitic stainless steel comprising (C+1/2N) up to 0.060 mass %, Si up to 1.0 mass %, Mn up to 5 mass %, S up to 0.003 mass %, S/Mn ratio up to 0.003, 15-20 mass % Cr, 5-12 mass % Ni, Cu up to 5 mass %, 0-3.0 mass % Mo and the balance being Fe except inevitable impurities under the condition that a value Md30 (representing a ratio of a strain-induced martensite) defined by the under-mentioned formula is controlled within a range of −60 to −10. Hardness increase of the steel sheet after being cold-rolled is preferably 20% or more as Vickers hardness. A metallurgical structure of the steel sheet is preferably adjusted to grain size number of #8 to #11 in a finish annealed state. The steel sheet is blanked with high dimensional accuracy, and a die life is also prolonged.

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 new austenitic stainless steel contains 0.1-1.0 mass % of Si and not more than 0.003 mass % of Al. Nonmetallic inclusion dispersed in a steel matrix is converted to MnO—SiO2—Al2O3 containing not less than 15 mass % of SiO2 and not more than 40 mass % of Al2O3. During steel making, molten steel is covered with basic slag and strongly deoxidized with a Si alloy whose Al content is controlled not more than 1.0 mass % in a vacuum or non-oxidizing atmosphere. The austenitic stainless steel sheet can be formed to an objective shape without occurrence of cracking due to its less crack-sensitivity and good formability.

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: The newly proposed austenitic stainless steel has composition consisting of (C+½N) up to 0.060 mass %, Si up to 1.0 mass %, Mn up to 5 mass %, S up to 0.006 mass %, 15-20 mass % Cr, 5-12 mass % Ni, Cu up to 5 mass %, 0-3.0 mass % Mo and the balance being Fe except inevitable impurities under the condition that a value Md3O (representing a ratio of a strain-induced martensite) defined by the under-mentioned formula is controlled within a range of −60 to −10. Hardness increase of the steel sheet after being cold-rolled is preferably 20% or more as Vickers hardness. A metallurgical structure of the steel sheet is preferably adjusted to grain size number of #8 to #11 in a finish annealed state. The steel sheet is blanked with high dimensional accuracy, and a die life is also prolonged.

Abstract: A new stainless steel sheet has a stainless steel substrate which contains Cu at a ratio of 1.0 wt. % or more and has Cu-enriched grains precipitated at a ratio of 0.2 vol. %. The Cu-enriched grains are exposed to the outside through pinholes in a passive film generated on the substrate. Cu is preferably condensed at a Cu/(Cr+Si) weight ratio of 0.1 or more or a Cu/(Si+Mn) weight ratio of 0.5 or more with respect to Cr, Si and Mn present in the passive film or at an outermost layer of the substrate. Precipitation of Cu-enriched grains and condensation of Cu effectively improve solderability and electric conductivity of the stainless steel sheet.

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 stainless steel excellent in fused-salt corrosion resistance having a composition specified in weight per cent including not more than 0.1% of C, not more than 2.0% of Mn, not less than 7.5% and less than 15.0% of Ni, 14.0-20.0% of Cr, more than 0.2% and not more than 4.0% of Si, and 1.0-4.0% of Al, and in some cases also including one or more of not more than 3.0% of Cu, not more than 3.0% of Mo, not more than 1.0% of Ti, not more than 1.0% of Zr, not more than 0.5% Y, and not more than 0.5% of REM, and satisfying the relationship Si%/Al%.ltoreq.1.0, the balance being Fe and unavoidable impurities.

Abstract: A ferritic stainless steel excellent in high temperature oxidation resistance and scale adhesion which consists essentially of in mass %, 0.03% maximum C, from 0.80% to 1.20% Si, from 0.60% to 1.50% Mn, from 11.0% to 15.5% Cr, from 0.20% to 0.80% Nb, 0.1% maximum Ti (inclusive of non-addition), not less than 0.02% and less than 0.30% Cu, 0.03% maximum N, 0.05% maximum Al (inclusive of non-addition), 0.012% maximum O, the balance being Fe and unavoidable impurities, and wherein the Mn/Si ratio is within the range between 0.7 and 1.5 and the alloying elements are adjusted so that the following relations (1), (2), and (3) and preferably (4) defined herein may be satisfied and wherein the steel exhibits an oxidation weight gain of not more than 0.02 kg/m.sup.2 and an amount of scale which has spalled of not more than 0.01 kg/m.sup.2 after a continuous heating in atmospheric air at 900.degree. C. for 100 hours and the steel exhibits an oxidation weight gain of not more than 0.4 kg/m.sup.

Abstract: A ferric stainless steel consists by weight of less than 0.03% carbon, less than 1% silicon, less than 1% manganese, less than 0.04% phosphorus, less than 0.03% sulphur, from 15% to 25% chromium, less than 0.03% nitrogen, from 3% to 6% aluminum, from 0.1% to 4% molybdenum. A small amount of rare-earth elements and yttrium of from 0.01% to 0.15% are added in the steel.

Abstract: A heat resisting ferritic stainless steel which comprises, by weight, up to 0.03% of C, from 0.1 to 0.8% of Si, from 0.6 to 2.0% of Mn, up to 0.006% of S, up to 4% of Ni, from 17.0 to 25.0% of Cr, from 0.2 to 0.8% of Nb, from 1.0 to 4.5% of Mo, from 0.1 to 2.5% of Cu, and up to 0.03% of N, and optionally one or more of appropriate amounts of Al, Ti, V, Zr, W, B and REM, the balance being Fe and unavoidable impurities, wherein the alloying elements are further adjusted so that the ratio of Mn%/S% is not less than 200, [Nb] defined by the equation: [Nb]=Nb%-8 (C%+N%) is not less than 0.2, and (Ni%+Cu%) is not more than 4. The stainless steel according to the invention is suitable for use in constructing an exhaust gas path-way of an automobile, particularly, a path-way from an engine to a converter, which is exposed to high temperatures, and which requires an improved low temperature toughness and a high resistance to weld cracking due to high temperatures.