Disclosed is a method for preparing a high-flatness metal foil suitable for making a metal mask, and the method comprises the following steps: forming a raw metal coarse foil; rolling the raw metal coarse foil at least once into a high-flatness metal foil; performing, by a heat treatment device, heat treatment processing on the precisely rolled metal foil according to a preset temperature and a preset time; using a tension leveler to perform tension leveling on the rolled and heat-treated metal foil; and obtaining a high-flatness metal foil after completion of the tension leveling and forming a rolled metal foil in a continuous forming process. The resulting metal foil has high flatness and low residual stress, which improves quality and performance of the metal foil and is suitable for the fabrication of fine metal masks.

A Fe-based alloy represented by a composition of (Fe.sub.(1-a)M.sup.1.sub.a).sub.100-b-c-d-e-f-gM.sup.2.sub.bM.sup.3.sub.cB.sub.dP.sub.eCu.sub.fTi.sub.g, wherein 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 one element selected from the group consisting of Si, Al, Ga, and Ge, and a, b, c, d, e, f, and g satisfy the following content conditions: 0≤a≤0.5, 0<b≤1.5, 0<c≤4, 7≤d≤13, 0.1≤e≤5, 0.6≤f≤1.5, and 0<g, is provided, wherein a full width at half maximum of an XRD main peak is 0.172 or more.

A Fe-based alloy represented by a composition of (Fe.sub.(1-a)M.sup.1.sub.a).sub.100-b-c-d-e-f-gM.sup.2.sub.bM.sup.3.sub.cB.sub.dP.sub.eCu.sub.fTi.sub.g, wherein 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 one element selected from the group consisting of Si, Al, Ga, and Ge, and a, b, c, d, e, f, and g satisfy the following content conditions: 0≤a≤0.5, 0<b≤1.5, 0<c≤4, 7≤d≤13, 0.1≤e≤5, 0.6≤f≤1.5, and 0<g, is provided, wherein a full width at half maximum of an XRD main peak is 0.172 or more.

This application provides Fe—Mn—Al—C lightweight steel, including: Fe, wherein a weight percentage of the Fe is greater than or equal to 50.4 wt %; Mn, wherein a weight percentage of the Mn is 25-35 wt %; Al, wherein a weight percentage of the Al is 6-12 wt %; C, wherein a weight percentage of the C is 0.8-2.0 wt %; and O, wherein a weight percentage of the O is 0.005-0.6 wt %. This application further provides a terminal to which the Fe—Mn—Al—C lightweight steel is applied, a production method for the Fe—Mn—Al—C lightweight steel, a steel mechanical part, and an electronic device. The lightweight steel in this application has low density, high strength, and high elongation.

Provided is a grain-oriented electrical steel sheet which has been subjected to heat-resistant magnetic domain refining treatment and can effectively suppress carburizing and nitriding during stress relief annealing. The grain-oriented electrical steel sheet has a plurality of grooves on one side that extend linearly across the rolling direction and are lined up at intervals in the rolling direction, and has at least a forsterite film on a surface of the steel sheet, where an average thickness of the forsterite film formed on the floor of the grooves is 0.45 μm or more, and a standard deviation a of the thickness is 0.34 μm or less.

A cold rolled and heat treated steel sheet having a composition including the following elements, expressed in % by weight: 0.1%≤carbon≤0.6% 4%≤manganese≤20% 5%≤aluminum≤15% 0≤silicon≤2% aluminium+silicon+nickel≥6.5% and can possibly contain one or more of the following optional elements: 0.01%≤niobium≤0.3%, 0.01%≤titanium≤0.2% 0.01%≤vanadium≤0.6% 0.01%≤copper≤2.0% 0.01%≤nickel≤2.0% cerium≤0.1% boron≤0.01% magnesium≤0.05% zirconium≤0.05% molybdenum≤2.0% tantalum≤2.0% tungsten≤2.0% the remainder being composed of iron and unavoidable impurities caused by processing, wherein the microstructure of said steel sheet includes in area fraction, 10 to 50% of austenite, the austenite phase optionally including intragranular kappa carbides, the remainder being regular ferrite and ordered ferrite of D03 structure (Fe,Mn,X).sub.3Al, optionally including up to 2% of intragranular kappa carbides (Fe,Mn).sub.3AlC.sub.x said steel sheet presenting a ultimate tensile strength higher than or equal to 900 MPa. It also deals with a manufacturing method and with use of such grade for making vehicle parts.

A cold rolled and heat treated steel sheet having a composition including the following elements, expressed in % by weight: 0.1%≤carbon≤0.6% 4%≤manganese≤20% 5%≤aluminum≤15% 0≤silicon≤2% aluminium+silicon+nickel≥6.5% and can possibly contain one or more of the following optional elements: 0.01%≤niobium≤0.3%, 0.01%≤titanium≤0.2% 0.01%≤vanadium≤0.6% 0.01%≤copper≤2.0% 0.01%≤nickel≤2.0% cerium≤0.1% boron≤0.01% magnesium≤0.05% zirconium≤0.05% molybdenum≤2.0% tantalum≤2.0% tungsten≤2.0% the remainder being composed of iron and unavoidable impurities caused by processing, wherein the microstructure of said steel sheet includes in area fraction, 10 to 50% of austenite, the austenite phase optionally including intragranular kappa carbides, the remainder being regular ferrite and ordered ferrite of D03 structure (Fe,Mn,X).sub.3Al, optionally including up to 2% of intragranular kappa carbides (Fe,Mn).sub.3AlC.sub.x said steel sheet presenting a ultimate tensile strength higher than or equal to 900 MPa. It also deals with a manufacturing method and with use of such grade for making vehicle parts.

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves. An average protrusion height of the surface protrusion extending along a longitudinal direction of the groove is more than 5 μm and not more than 10 μm. When the surface protrusion is viewed in a cross section including the longitudinal direction of the groove and a normal direction of the steel sheet surface, the surface protrusion includes specific portions each having a height of 50% or more with respect to a height of each peak point appearing on a profile line of the surface protrusion. In the longitudinal direction of the groove, the total length of the specific portions is a length of 30% or more with respect to an overall length of the surface protrusion.

The present invention can provide light-colored magnetic particles having a zirconium oxide coating layer formed on a magnetic core, and having a silver coating layer formed on the zirconium oxide coating layer, and a part of the surface of the zirconium oxide coating layer is exposed to the outside, but chemical resistance is excellent, and thus the magnetic particles hardly cause a change of magnetic characteristics so as to be suitable for security elements.

A solid wire for electroslag welding, including Fe and, by mass % based on a total mass of the wire: C: more than 0% and 0.03% or less; Si: more than 0% and 0.10% or less; Mn: more than 0% and 0.25% or less; Ni: 10.5%-14.0%; S: more than 0% and 0.010% or less; Al: more than 0% and 0.250% or less; REM: 0.002%-0.080%; and O: more than 0% and 0.0090% or less.