A Fe—Cr alloy having a chemical composition with increased Si and Al contents, in which the chemical composition satisfies the following formula (1) in terms of the Si content, Al content, and Cr content:
14.0≤% Si+1.15×% Al+0.35×% Cr   (1).

A method of production non grain-oriented Fe—Si steel sheet is provided. The method includes the steps of melting a steel composition that contains in weight percentage: C≦0.006, 2.0≦Si≦5.0, 0.1≦Al≦3.0, 0.1≦Mn≦3.0, N≦0.006, 0.04≦Sn≦0.2, S≦0.005, P≦0.2, Ti≦0.01, the balance being Fe and other inevitable impurities, casting said melt into a slab, reheating said slab, hot rolling said slab, coiling said hot rolled steel, optionally annealing the hot rolled steel, cold rolling, annealing and cooling the cold rolled steel down to room temperature.

Disclosed is a non-oriented electrical steel sheet that is low in iron loss and exhibits excellent magnetic properties even when subjected to final annealing at high temperature. The non-oriented electrical steel sheet can be obtained from a steel (low-Al steel) having a chemical composition containing, in mass %, C: 0.005% or less, Si: 1.0% to 4.5%, Mn: 0.02% to 2.0%, Sol.Al: 0.001% or less, P: 0.2% or less, S+Se: 0.0010% or less, N: 0.005% or less, O: 0.005% or less, and Cu: 0.02% to 0.30%, and the balance consisting of Fe and incidental impurities.

Disclosed is a steel composition including specified ranges of Ni; Mo; Co; Mo+Co+Si+Mn+Cu+W+V+Nb+Zr+Ta+Cr+C; Co+Mo; Ni+Co+Mo; and traces of Al; Ti; N; Si; Mn; C; S; P; B; H; O; Cr; Cu; W; Zr; Ca; Mg; Nb; V; and Ta in specified ranges; the remainder being iron and impurities. The inclusion population, as observed by image analysis over a polished surface measuring 650 mm.sup.2 if hot-formed or hot-rolled; and measuring 800 mm.sup.2 if cold-rolled, does not contain non-metallic inclusions of diameter >10 μm, and, in the case of a hot-rolled sheet, does not contain more than four non-metallic inclusions of diameter 5-10 μm over 100 mm.sup.2, the observation being performed by image analysis over a polished surface measuring 650 mm.sup.2.

The austenitic heat resistant steel of the embodiment contains: 24 to 50% by mass of Ni, 5 to 13% by mass of Cr, 0.1 to 12% by mass of Co, 0.1 to 5% by mass of Nb, 0.1 to 0.5% by mass of V, 1.90 to 2.35% by mass of Ti, 0.01 to 0.30% by mass of Al, 0.001 to 0.01% by mass of B, 0.001 to 0.1% by mass of C, and the balance being Fe and inevitable impurities.

A ferritic stainless steel sheet comprises a chemical composition containing, in mass %, C: 0.030% or less, Si: 3.0% or less, Mn: 1.0% or less, P: 0.040% or less, S: 0.010% or less, Cr: 11.0% to 30.0%, Al: 8.0% to 20.0%, Ni: 0.05% to 0.50%, N: 0.020% or less, and at least one selected from the group consisting of Zr: 0.01% to 0.20% and Hf: 0.01% to 0.20%, with a balance consisting of Fe and inevitable impurities.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, C at 0.005% or less (excluding 0%), Si at 0.5 to 2.4%, Mn at 0.4 to 1.0%, S at 0.005% or less (excluding 0%), Al at 0.01% or less (excluding 0%), N at 0.005% or less (excluding 0%), Ti at 0.005% or less (excluding 0%), Cu at 0.001 to 0.02%, and the balance of Fe and inevitable impurities, and satisfies Formula 1 below, wherein a volume fraction of grains in which an angle formed by a {111} surface and a rolling surface of the steel sheet is 15° or less is 27% or more.

[Mn]/([Si]+150×[Al])≤0.35   [Formula 1]

(In Formula 1, [Mn], [Si], and [Al] are contents (wt %) of Mn, Si, and Al, respectively.)

A non-oriented electrical steel sheet having high magnetic flux density and a low iron loss at a high frequency is produced by subjecting a slab containing, in mass %, C: not more than 0.0050%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, P: not more than 0.10%, S: not more than 0.0050%, Al: 0.3 to 2.0%, N: not more than 0.0050% and Zn: 0.0005 to 0.0050% to a hot rolling, a hot-band annealing, a cold rolling and a finish annealing, a dew point in the hot-band annealing is set to 0 to 70 ° C. and an atmosphere of the finish annealing has a nitrogen content of not more than 30 vol % and a dew point of not higher than −20° C., and a ratio of the amount of nitrogen present as AlN in an entire sheet thickness to the amount of nitrogen present as AlN in a layer from one-side surface of steel sheet to a depth of 1/20 of sheet thickness is made to not less than 5.0.

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of the primary coating to the steel sheet is provided. This is provided with a base metal steel sheet containing a predetermined chemical composition and a primary coating formed on a surface of the base metal steel sheet and containing Mg.sub.2SiO.sub.4 as a main constituent. A peak position of Al emission intensity obtained when performing elemental analysis by glow discharge optical emission spectrometry from a surface of the primary coating in a thickness direction of the grain-oriented electrical steel sheet is arranged within a range of 2.0 to 10.0 μm from the surface of the primary coating in the thickness direction. A number density of Al oxides of a size of 0.2 μm or more in terms of a circle equivalent diameter based on the area at the peak position of Al emission intensity is 0.032 to 0.20/μm.sup.2, and, in a 100 μm×100 μm distribution chart of Al oxides at the peak position of Al emission intensity obtained by glow discharge optical emission spectrometry, if dividing the distribution chart by 10 μm×10 μm grid section, a ratio of a number of grid sections not containing the Al oxides to the total number of grid sections in the distribution chart is 5% or less.

A cold-rolled and recrystallization-annealed flat steel product may include a ferritic microstructure, which possesses optimized formability and suitability for a wide variety of applications, including painting, for example. The flat steel product may include a steel comprising (in percent by weight): C: 0.0001%-0.003%, Si: 0.001%-0.025%, Mn: 0.05%-0.20%, P: 0.001%-0.015%, Al: 0.02%-0.055%, Ti: 0.01%-0.1%. The steel may further include at least one of Cr: 0.001%-0.05%, V: up to 0.005%, Mo: up to 0.015%, or N: 0.001%-0.004%, which may have the following mechanical properties: Rp0.2≦180 MPa, Rm≦340 MPa, A80≦40%, and n value ≦0.23. At least one surface may have an arithmetic mean roughness Ra of 0.8-1.6 μm and a peak count RPc of 75/cm. The present disclosure also concerns methods for producing flat steel products.