A method for manufacturing a grain-oriented electrical steel sheet according to an aspect of the present invention includes a step of obtaining a hot-rolled steel sheet by carrying out hot rolling on a slab containing a predetermined component composition with a remainder including Fe and impurities, a step of obtaining a hot-rolled annealed sheet by carrying out hot-rolled sheet annealing as necessary, a step of carrying out pickling to obtain a pickled sheet, a step of carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing, a step of applying an annealing separating agent including MgO to a surface and then carrying out final annealing to obtain a final-annealed sheet, and a step of applying an insulating coating and then carrying out flattening annealing.

An Fe-based nanocrystalline alloy is represented by Composition Formula, (Fe.sub.(1-a)M.sup.1a).sub.100-b-c-d-e-gM.sup.2.sub.bB.sub.cP.sub.dCu.sub.eM.sup.3.sub.g, where M.sup.1 is at least one element selected from the group consisting of Co and Ni, M.sup.2 is at least one element selected from the group consisting of Nb, Mo, Zr, Ta, W, Hf, Ti, V, Cr, and Mn, M.sup.3 is at least two elements selected from the group consisting of C, Si, Al, Ga, and Ge but necessarily includes C, and 0≤a≤0.5, 1.5<b≤3, 10≤c≤13, 0<d≤4, 0<e≤1.5, and 8.5≤g≤12.

An Fe-based nanocrystalline alloy is represented by Composition Formula, (Fe.sub.(1-a)M.sup.1a).sub.100-b-c-d-e-gM.sup.2.sub.bB.sub.cP.sub.dCu.sub.eM.sup.3.sub.g, where M.sup.1 is at least one element selected from the group consisting of Co and Ni, M.sup.2 is at least one element selected from the group consisting of Nb, Mo, Zr, Ta, W, Hf, Ti, V, Cr, and Mn, M.sup.3 is at least two elements selected from the group consisting of C, Si, Al, Ga, and Ge but necessarily includes C, and 0≤a≤0.5, 1.5<b≤3, 10≤c≤13, 0<d≤4, 0<e≤1.5, and 8.5≤g≤12.

This steel sheet has a predetermined chemical composition, and, on a surface parallel to a surface at a ¼ position of a sheet thickness in a sheet thickness direction from the surface, with respect to a total area of three types of oxides of MnO, Cr.sub.2O.sub.3 and Al.sub.2O.sub.3 having a major axis of more than 1.0 μm, a total area ratio of the MnO and the Cr.sub.2O.sub.3 is 98.0% or more, and an area ratio of the Al.sub.2O.sub.3 is 2.0% or less.

This steel sheet has a predetermined chemical composition, and, on a surface parallel to a surface at a ¼ position of a sheet thickness in a sheet thickness direction from the surface, with respect to a total area of three types of oxides of MnO, Cr.sub.2O.sub.3 and Al.sub.2O.sub.3 having a major axis of more than 1.0 μm, a total area ratio of the MnO and the Cr.sub.2O.sub.3 is 98.0% or more, and an area ratio of the Al.sub.2O.sub.3 is 2.0% or less.

Steel for glass lining, comprising the following chemical elements in mass percent: C: 0.015-0.060%, Si: 0.01-0.50%, Mn: 0.20-1.5%, P: 0.005-0.10%, Al: 0.010-0.070%, Ti: 0.10-0.30%, and the balance of Fe and other inevitable impurities. The microstructure of the steel for glass lining is a ferrite or a combination of a ferrite and a cementite. In addition, also disclosed is a production method for steel for glass lining, comprising the steps of (1) smelting, refining, and continuous casting to obtain a slab; (2) heating, the heating temperature being 1050-1250° C.; (3) hot rolling, the final temperature of hot rolling being controlled to be 800-920° C.; (4) cooling; and (5) thermal treatment. The steel for glass lining has excellent machinability and low temperature toughness, and also has excellent lining performance.

Steel for glass lining, comprising the following chemical elements in mass percent: C: 0.015-0.060%, Si: 0.01-0.50%, Mn: 0.20-1.5%, P: 0.005-0.10%, Al: 0.010-0.070%, Ti: 0.10-0.30%, and the balance of Fe and other inevitable impurities. The microstructure of the steel for glass lining is a ferrite or a combination of a ferrite and a cementite. In addition, also disclosed is a production method for steel for glass lining, comprising the steps of (1) smelting, refining, and continuous casting to obtain a slab; (2) heating, the heating temperature being 1050-1250° C.; (3) hot rolling, the final temperature of hot rolling being controlled to be 800-920° C.; (4) cooling; and (5) thermal treatment. The steel for glass lining has excellent machinability and low temperature toughness, and also has excellent lining performance.

The invention relates to a method for producing a rolling bearing ring featuring an improved robustness against the formation of white etching cracks (WEC), wherein the rolling bearing component, which is made of a hypo-eutectoid heat-treated steel containing C in an amount of 0.4-0.55% and Cr in an amount of 0.5-2.0% in order to form a hardened boundary layer, is inductively heated, then quenched and subsequently tempered.

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).