Abstract: A high-strength surface-coated steel sheet includes a base steel sheet having a composition by mass of C: 0.01 to 0.20%, Si: 0.01 to 0.50%, Mn: 0.10 to 2.50%, P: 0.005 to 0.050%, B: 0.0005 to 0.010%, Ti: 0.01 to 0.20%, Nb: 0 to 0.10%, Mo: 0 to 0.50%, Cr: 0 to 0.50%, Al: 0.01 to 0.10%, and the balance of Fe and inevitable impurities; and a Zn—Al—Mg-based coating layer disposed on a surface of the base steel sheet, The steel sheet has a diffusible hydrogen concentration in the base steel sheet of 0.30 ppm or less and having a time until occurrence of red rust of 7000 hours or more as measured by a salt spray test. The high-strength hot-dip Zn—Al—Mg-based-plated steel sheet has a significantly lowered in-steel concentration of hydrogen which has entered the steel in a plating line and exhibits excellent corrosion resistance.

Abstract: A steel sheet hot-dip coated with a Zn—Al—Mg-based system, wherein the steel sheet material has a predetermined chemical composition; a Ti/C equivalent ratio represented by Formula (1) described in the specification is 0.4 to 1.5; a bainitic ferrite single phase or a phase including a bainitic ferrite phase and a ferrite phase exists as a main phase; the area ratio of a hard second phase and cementite is 3% or less; the ratio of small-angle boundaries with a difference in crystal orientation of 2° to 15° is 30% to 75%; and Ti-containing carbides having an average particle size of 20 nm or less are dispersed and precipitated and a method of manufacturing thereof.

Abstract: A steel sheet hot-dip coated with a Zn—Al—Mg-based system, wherein the steel sheet material has a predetermined chemical composition; a Ti/C equivalent ratio represented by Formula (1) described in the specification is 0.4 to 1.5; a bainitic ferrite single phase or a phase including a bainitic ferrite phase and a ferrite phase exists as a main phase; the area ratio of a hard second phase and cementite is 3% or less; the ratio of small-angle boundaries with a difference in crystal orientation of 2° to 15° is 30% to 75%; and Ti-containing carbides having an average particle size of 20 nm or less are dispersed and precipitated and a method of manufacturing thereof.

Abstract: A stainless steel plate is manufactured by performing temper rolling using a dull roller after the finish cold rolling and bright annealing. The stainless steel plate has an arithmetic mean roughness Ra of 0.2 to 1.2 ?m in a direction perpendicular to the rolling direction of the steel plate surface. Furthermore, the stainless steel plate has a transfer ratio of 15 to 70% which is an area ratio of a portion onto which a dull pattern is transferred relative to the steel plate surface. In addition, the micro-pits being formed in the steel plate surface, having a depth of 0.5 ?m or more, and having an opening area of 10 ?m2 or more, have an existing density in the steel plate surface of 10.0 or less per 0.01 mm2, and an opening area ratio in the steel plate surface of 1.0% or less.

Abstract: A stainless steel plate is manufactured by performing temper rolling using a dull roller after the finish cold rolling and bright annealing. The stainless steel plate has an arithmetic mean roughness Ra of 0.2 to 1.2 ?m in a direction perpendicular to the rolling direction of the steel plate surface. Furthermore, the stainless steel plate has a transfer ratio of 15 to 70% which is an area ratio of a portion onto which a dull pattern is transferred relative to the steel plate surface. In addition, the micro-pits being formed in the steel plate surface, having a depth of 0.5 ?m or more, and having an opening area of 10 ?m2 or more, have an existing density in the steel plate surface of 10.0 or less per 0.01 mm2, and an opening area ratio in the steel plate surface of 1.0% or less.

Abstract: A Fe-Cr soft magnetic material has electric resistivity not less than 50 &mgr;&OHgr;·cm and a metallurgical structure occupied by a ferrite phase at a surface ratio of 95% or more. A number of fine precipitates of 1 &mgr;m or less in particle size is controlled at a ratio not more than 6×105/mm2. The Fe-Cr alloy has the composition (expressed in mass or weight %) of C up to 0.05%, N up to 0.05%, Si up to 3.0%, Mn up to 1.0%, P up to 0.04%, S up to 1.0%, 5.0-20.0% Cr, Al up to 4.0%, 0-3% Mo, 0-0.5% Ti and the balance being essentially Fe under the conditions of (1) and (2). The Fe-Cr soft magnetic material is useful as a core, a yoke or the like installed in various types of magnetic sensors such as electric power steering, fuel injection systems for vehicles and A.C. magnetic circuits of solenoid valves, due to production of high magnetic induction in a high-frequency low-magnetic field: 4.3×%Cr+19.1×%Si+15.1×%Al+2.5×%Mo≧40.

Abstract: A newly proposed Fe-Cr soft magnetic material has electric resistivity not less than 50 &mgr;&OHgr;·cm and a metallurgical structure occupied by a ferrite phase at a surface ratio of 95% or more. A number of fine precipitated of 1 &mgr;m or less in particle size is controlled at a ratio not more than 6×105/mm2. The Fe-Cr alloy has the composition of C up to 0.05%, N up to 0.05%, Si up to 3.0%, Mn up to 1.0%, P up to 0.04%, S up to 1.0%, 5.0-20.0% Cr, Al up to 4.0%, 0-3% Mo, 0-0.5% Ti and the balance being essentially Fe under the conditions of (1) and (2). The Fe-Cr soft magnetic material is useful as a core, a yoke or the like installed in various types of magnetic sensors such as electric power steering, fuel injection systems for vehicles and A.C magnetic circuits of solenoid valves, due to production of great magnetic induction in a high-frequency low-magnetic field.