Abstract: Exemplary embodiments of the present invention can provide a hot dip galvannealed steel sheet which has excellent corrosion resistance, workability, coatability and appearance. The exemplary galvannealed sheet can include an ultra-low carbon steel sheet having a plating layer which includes about 8 to 13% Fe, about 0.05 to 1.0% Ni, about 0.15 to 1.5% Al, and a balance of Zn and unavoidable impurities. An exemplary method for producing a hot dip galvannealed steel sheet is also provided which can include cleaning an annealed ultra-low carbon steel sheet, preplating it with Ni, rapidly heating the sheet in a nonoxidizing or reducing atmosphere, plating the sheet in a galvanization bath containing Al, wiping it, then rapidly reheating it and either cooling the sheet without any soaking time or soaking and holding it for less than 15 seconds and then cooling it.

Abstract: The present invention provides: a high-strength high-ductility hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet excellent in ductility, which improves non-plating defects and plating adhesion after severe deformation, and a method of producing the same; a high-strength and high-ductility hot-dip galvanized steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having superior appearance and workability, which suppresses the generation of non-plating defects, and a method of producing the same; and a high-strength hot-dip galvannealed steel sheet and a high-strength hot-dip galvanized steel sheet, which suppress non-plating defects and surface defects and have both corrosion resistance, in particular corrosion resistance in an environment containing chlorine ion, and high ductility, and a meth

Abstract: One aspect of the steel sheet having high Young's modulus includes in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, S: 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities, wherein one or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer is 10 or more, and a Young's modulus in a rolling direction is more than 230 GPa. Another aspect of the steel sheet having high Young's modulus includes, in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 0.1 to 5.0%, P: 0.15% or less, S: 0.015% or less, Al: 0.15% or less, N: 0.01% or less, and further comprises one or two or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.

Abstract: The present invention provides: a high-strength high-ductility hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet excellent in ductility, which improves non-plating defects and plating adhesion after severe deformation, and a method of producing the same; a high-strength and high-ductility hot-dip galvanized steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having superior appearance and workability, which suppresses the generation of non-plating defects, and a method of producing the same; and a high-strength hot-dip galvannealed steel sheet and a high-strength hot-dip galvanized steel sheet, which suppress non-plating defects and surface defects and have both corrosion resistance, in particular corrosion resistance in an environment containing chlorine ion, and high ductility, and a meth

Abstract: The present invention provides: a high-strength high-ductility hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet excellent in ductility, which improves non-plating defects and plating adhesion after severe deformation, and a method of producing the same; a high-strength and high-ductility hot-dip galvanized steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having superior appearance and workability, which suppresses the generation of non-plating defects, and a method of producing the same; and a high-strength hot-dip galvannealed steel sheet and a high-strength hot-dip galvanized steel sheet, which suppress non-plating defects and surface defects and have both corrosion resistance, in particular corrosion resistance in an environment containing chlorine ion, and high ductility, and a meth

Abstract: In order to provide an alkali-soluble-film surface-lubricated metal product excellent in moldability and long-term stable film-removability independent of the film drying temperature, an alkali-soluble lubricating film mainly comprising an alkali-soluble polyurethane aqueous composition containing a polyether polyol as a skeleton and also containing a carboxyl group within the molecule, and a lubricating function-imparting agent in an amount of 1 to 30 mass % based on the alkali-soluble polyurethane aqueous composition is coated on both surfaces or one surface of a metal to have a film thickness of 0.5 to 10 &mgr;m, thereby constituting an alkali-soluble-film surface-lubricated metal product excellent in moldability and long-term stable film-removability independent of the film drying temperature, wherein the elastic modulus of the film after coating is from 0.5 to 20 GPa at 25° C.

Abstract: A soluble lubricating surface-treated stainless steel sheet with excellent shapability for fuel tanks, comprising a substrate having on both surfaces or one surface thereof a soluble lubricating resin film. Preferably, the soluble lubricating resin film mainly comprises (A) an alkali-soluble polyurethane resin composition containing a carboxyl group or a sulfonic acid group within the molecule and having a glass transition point of 100° C. or more as a dry film and (B) a lubricating function-imparting agent in an amount of from 1 to 30% by mass based on the polyurethane composition.

Abstract: To provide a steel sheet excellent in painting bake hardenability and anti aging property at room temperature: containing, in mass, 0.0001 to 0.20% of C, 2.0% or less of Si, 3.0% or less of Mn, 0.15% or less of P, 0.015% or less of S, and, in addition, 010% or less of Al and 0.001 to 0.10% of N so as to satisfy the expression 0.52Al/N<5 and, further, one or more of 2.5% or less of Cr, 1.0% or less of Mo and 0.1% or less of V so as to satisfy the expression (Cr+3.5MO+39V) ≧0.1, with the balance consisting of Fe and unavoidable impurities; having the value of BH170, evaluated after applying a 2% tensile deformation and then a heat treatment at 170° C. for 20 min., being 45 MPa or more, and any of the value of BH160, evaluated after applying a 2% tensile deformation and then a heat treatment at 160° C. for 10 min., and the value of BH150, evaluated after applying a 2% tensile deformation and then a heat treatment at 150° C. for 10 min.

Abstract: A surface-lubricated metal product, with excellent shapability, comprising a metal having coated on both surfaces, or one surface, thereof an alkali-soluble lubricating film mainly comprising an alkali-soluble polyurethane aqueous composition containing a carboxyl group or a sulfonic acid group within the molecule, and a lubricating function-imparting agent in an amount of 1 to 30 mass % based on the alkali-soluble polyurethane aqueous composition, the film being coated to have a film thickness of 0.5 to 10 &mgr;m and the elastic modulus of the film after coating being 0.5 to 20 GPa at 25° C.

Abstract: To provide a steel sheet excellent in painting bake hardenability and anti aging property at room temperature: containing, in mass, 0.0001 to 0.20% of C, 2.0% or less of Si, 3.0% or less of Mn, 0.15% or less of P, 0.015% or less of S, and, in addition, 010% or less of Al and 0.001 to 0.10% of N so as to satisfy the expression 0.52Al/N<5 and, further, one or more of 2.5% or less of Cr, 1.0% or less of Mo and 0.1% or less of V so as to satisfy the expression (Cr+3.5MO+39V) ≧0.1, with the balance consisting of Fe and unavoidable impurities; having the value of BE170, evaluated after applying a 2% tensile deformation and then a heat treatment at 170° C. for 20 min., being 45 MPa or more, and any of the value of BH160, evaluated after applying a 2% tensile deformation and then a heat treatment at 160° C. for 10 min., and the value of BH150, evaluated after applying a 2% tensile deformation and then a heat treatment at 150° C. for 10 min.

Abstract: A soluble lubricating surface-treated stainless steel sheet with excellent shapability for fuel tanks, comprising a substrate having on both surfaces or one surface thereof a soluble lubricating resin film. Preferably, the soluble lubricating resin film mainly comprises (A) an alkali-soluble polyurethane resin composition containing a carboxyl group or a sulfonic acid group within the molecule and having a glass transition point of 100° C. or more as a dry film and (B) a lubricating function-imparting agent in an amount of from 1 to 30% by mass based on the polyurethane composition.

Abstract: Surface treated steel sheet for fuel containers having excellent corrosion resistance, formability and weldability is provided. A steel sheet containing 0.0005-0.0040% of C, 0.005-0.020% of P, 0.0005-0.0040% of N, and 0.0005-0.0030% of B has on at least one surface a first coating layer constituted as a Zn coating layer of a coating weight of 5-80g/m.sup.2 and a second coating layer on the first coating layer constituted as a Ni coating layer of a coating weight of 0.5-10g/m.sup.2. The Zn coating layer is composed of Zn, Zn--Fe alloy or Zn--Ni alloy. Alternatively, one surface is formed with the first coating layer and the second coating layer and the other surface is formed with a Zn coating layer.

Abstract: A steel material and a steel pipe each exhibiting an excellent corrosion resistance in an environment containing a wet carbon dioxide and a small amount of hydrogen sulfide are produced at low cost and with high productivity, a steel slab which contains, in wt %, 0.01 to 0.6% of Si, 0.02 to 1.8% of Mn, 7.5 to 14.0% of Cr, 1.5 to 4.0% of Cu and 0.005 to 0.1% of Al, which reduces C to not more than 0.02%, N to not more than 0.02%, P to not more than 0.025% and S to not more than 0.01%, and whose balance consists of Fe and unavoidable impurities, is heated to a temperature of 1,100.degree. to 1,300.degree. C., hot rolling is finished at a rolling finish temperature of not less than 800.degree. C. and a cumulative rolling reduction quantity at a temperature not more than 1,050.degree. C. is at least 65%, and cooling is carried out at a cooling rate of less than 0.02.degree. C./sec to at least 500.degree. C. so as to substantially convert the metallic structure to ferrite.

Abstract: A steel pipe having excellent corrosion resistance in an environment containing wet carbon dioxide and a small amount of hydrogen sulfide and having also excellent weldability is produced at a low production cost and with high productivity. The production method comprises heating to a temperature of 1,050.degree. to 1,300.degree. C. a slab containing, in terms of wt %, 0.01 to less than 1.2% of Si, 0.02 to 3.0% of Mn, 7.5 to 14.0% of Cr and 0.005 to 0.5% of Al, reduced C, N, P and S contents, at least one of Cu, Ni, Co, Mo and W, a balance of Fe and unavoidable impurities, and having an MC value of at least 0, finishing hot rolling within an austenite monophase temperature range, coiling the steel sheet as a hot coil having a sheet thickness of 3.0 to 25.4 mm, cooling the coil at a cooling rate of at least 0.01.degree. C./sec to at least 500.degree. C. to convert the steel sheet to a steel substantially consisting of martensite, reheating the steel to a temperature of 550.degree. C. to not more than an A.sub.

Abstract: The present invention relates to a steel having excellent corrosion resistance and workability and more particularly to a steel having excellent corrosion resistance and workability in an exhaust system of internal combustion engines in, for example, internal combustion engines in automobiles and ships. A steel having excellent corrosion resistance and a steel having excellent corrosion resistance and workability, characterized by comprising Si: not less than 0.01 to less than 1.2%, Mn: 0.1 to 1.5%, Cr: 2.5 to 9.9%, and Al: more than 3.0 to 8.0%, and, reduced to, C: not more than 0.02%, P: not more than 0.03%, S: not more than 0.01%, and N: not more than 0.02%, and further comprising 0.01 to 0.5% in total of Nb, V, Ti, Zr, Ta, and Hf so as to meet a particular conditional formula, or further comprising at least one member selected from Cu, Mo, Sb, Ni, W, rare earth elements, and Ca, with the balance consisting of Fe and unavoidable impurities.

Abstract: This invention relates to a steel excellent in corrosion resistance and processability, and more particularly to a steel excellent in corrosion resistance for the exhaust system of an internal combustion engine of, for example, an automobile or ship. Such steel contains not less than 0.01% and less than 1.2% of Si, 0.1-1.5% of Mn, 5.5-9.9% of Cr and 0.3-3.0% of Al, is reduced to a content of C of not more than 0.02%, P of not more than 0.03%, S of not more than 0.01% and N of not more than 0.02%, contains Nb, V, Ti, Zr, Ta and Hf in a total amount of 0.01-0.5%, satisfies the relationship set out below, and optionally contains in addition one or more of Cu, Mo, Sb, Ni, W, rare earth elements, and Ca, the remainder being Fe and unavoidable impurities.(Nb/93)+(V/51)+(Ti/48)+(Zr/91)+(Ta/181)+(Hf/179)-0.8.times.[(C/12)+(N/14)]. gtoreq.

Abstract: An alloy exhibiting corrosion resistance in a combustion environment where V, Na, S and Cl are present comprises, in weight percent, not more than 0.05% C, 0.02-0.5% Si, 0.02-0.5% Mn, 15-35% Cr, 0.5-4% Mo, 10-40% Co, 5-15% Fe, 0.5-5% W, 0.0003-0.005% Ca and the remainder of Ni at a content of not less than 4% and unavoidable impurities, provided that Cr (%)+0.5Ni (%)+3Mo (%).gtoreq.30 (%) and Ni (%)+0.5Co (%).gtoreq.Cr (%)+Mo (%)+W (%). A composite steel tube exhibiting corrosion resistance in a combustion environment where V, Na, S and Cl are present comprises an inner tube constituted of Cr-containing boiler tube and an outer tube constituted of the alloy.

Abstract: An alloy exhibiting corrosion resistance in a combustion environment where V, Na, S and Cl are present comprises, in weight percent, not more than 0.05% C, 0.02-0.5% Si, 0.02-0.5% Mn, 15-35% Cr, 0.5-4% Mo, more than 40% but not more than 60% Co, 5-15% Fe, 0.5-5% W, 0.0003-0.005% Ca and the remainder of Ni at a content of not less than 4% and unavoidable impurities, provided that Cr (%)+0.5Ni (%)+3Mo (%).gtoreq.30 (%). A composite steel tube exhibiting corrosion resistance in a combustion environment where V, Na, S and Cl are present comprises an inner tube constituted of Cr-containing boiler tube and an outer tube constituted of the alloy.

Abstract: A high-strength martensitic stainless steel excellent in corrosion resistance and stress corrosion cracking resistance, the composition of which comprises: 0.1% or less carbon, 1% or less silicon, 2% or less manganese, 8-14% chromium, 1.2-4.5% copper, 0.005-0.2% aluminum, 0.01-0.15% nitrogen, and the balance of iron except incidental elements. The stainless steel can contain nickel, molybdenum, tungsten, vanadium, titanium, niobium, etc. under the fixed conditions in addition to the above elements. The heat treatment of the stainless steel comprises: the step of austenitizing at temperatures of 920.degree. C. to 1,000.degree. C., the step of cooling at a cooling rate equal to or higher than the air cooling rate, the step of tempering at temperatures between 580.degree. C. and A.sub.cl point, and the step of cooling at a cooling rate higher than the air cooling rate.

Abstract: A high-strength martensitic stainless steel excellent in corrosion resistance and stress corrosion cracking resistance, the composition of which comprises: under 0.03% carbon, 1% or less silicon, 2.3-7.0% manganese, 8-14% chromium, 0.005-0.2% aluminum, 0.005-0.15% nitrogen, and the balance of iron except incidental elements. The stainless steel can contain nickel, molybdenum, tungsten, copper, vanadium, titanium, niobium, zirconium, tanatalum, hafnium, calcium and rare earth elements under the fixed conditions in addition to the above elements. Heat treatment of the stainless steel comprises: the step of austenitizing at temperatures of 920.degree. C. to 1,100.degree. C., the step of cooling at a cooling rate equal to or higher than the air cooling rate, the step of tempering at temperatures between 580.degree. C. and A.sub.cl point, and the step of cooling at a cooling rate equal to or higher than the air cooling rate.