A soft magnetic powder contains a particle having a composition represented by Fe.sub.xCu.sub.aNb.sub.b(Si.sub.1-yB.sub.y).sub.100-x-a-b, and 0.3≤a≤2.0, 2.0≤b≤4.0, and 72.5≤x≤75.5, and y is a number satisfying f(x)≤y≤0.99, and f(x)=(4×10.sup.−34)×17.56. The particle includes a crystal grain having a grain size of 1.0 nm to 30.0 nm, a Cu segregation portion, and a crystal grain boundary. A content proportion of the crystal grain is 30% or more. When the Cu segregation portion positioned in a surface layer portion and having a grain size of 1.0 nm to 5.0 nm is referred to as a first Cu segregation portion, and the Cu segregation portion positioned in an inner portion and having a grain size of 3.0 nm to 10.0 nm is referred to as a second Cu segregation portion, a number proportion of the first Cu segregation portion is 80% or more, and a number proportion of the second Cu segregation portion is 80% or more.

A neodymium-iron-boron permanent magnet material, a preparation method, and an application. The neodymium permanent magnet material includes R, Al, Cu, and Co; R comprises RL and RH; RL comprises one or many light rare earth elements among Nd, La, Ce, Pr, Pm, Sm, and Eu; RH comprises one or many heavy rare earth elements among Tb, Gd, Dy, Ho, Er, Tm, Yb, Lu, and Sc; the neodymium-iron-boron permanent magnet material satisfies the following relations: (1) B/R: 0.033-0.037; (2) AI/RH: 0.12-2.7. The neodymium-iron-boron permanent magnet material has uniquely advantageous magnetic and mechanical properties, with Br≥13.12 kGs, Hcj≥17.83 kOe, and bending strength≥409 MPa.

A neodymium-iron-boron permanent magnet material, a preparation method, and an application. The neodymium permanent magnet material includes R, Al, Cu, and Co; R comprises RL and RH; RL comprises one or many light rare earth elements among Nd, La, Ce, Pr, Pm, Sm, and Eu; RH comprises one or many heavy rare earth elements among Tb, Gd, Dy, Ho, Er, Tm, Yb, Lu, and Sc; the neodymium-iron-boron permanent magnet material satisfies the following relations: (1) B/R: 0.033-0.037; (2) AI/RH: 0.12-2.7. The neodymium-iron-boron permanent magnet material has uniquely advantageous magnetic and mechanical properties, with Br≥13.12 kGs, Hcj≥17.83 kOe, and bending strength≥409 MPa.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt%, Si: 2.2 to 4.5 %, Mn: 0.5 % or less (excluding 0 %), AI: 0.001 to 0.5 %, Sn: 0.07 to 0.25 %, and N: 0.0010 to 0.0090 %, and the balance of Fe and inevitable impurities.

A surface layer portion existing in an inner direction from a surface of the steel sheet and a central portion existing inside the surface layer portion are included, and the central portion includes N at 0.005 wt% or less, and the surface layer portion further includes N at 0.001 wt% or more compared to the central portion; and the surface layer portion has an average grain size of 60 .Math.m or less, while the central portion has an average grain size of 70 to 300 .Math.m.

A method for manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises the steps of: hot-rolling a slab to prepare a hot-rolled sheet, the slab containing, in wt %, 2.0 to 6.0% of Si, 0.04 to 0.12% of Mn, 0.001 to 0.022% of N, 0.027 to 0.060% of C, 0.01 to 0.08% of Nb, 0.01% or less of Ti, and the balance of Fe and other inevitable impurities; cold-rolling the hot-rolled sheet to prepare a cold-rolled sheet; and subjecting the primarily recrystallization-annealed cold-rolled sheet to secondary recrystallization annealing.

The present invention provides a steel sheet having excellent wear resistance and composite corrosion resistance, and a method of manufacturing same. According to one example of the present invention, a corrosion-resistant steel sheet having excellent wear resistance and composite corrosion resistance comprises, in wt %: 0.04-0.10% of carbon (C); 0.10% or less (excluding 0%) of silicon (Si); 0.20-0.35% of copper (Cu); 0.1-0.2% of nickel (Ni); 0.05-0.15% of antimony (Sb); 0.07-0.22% of tin (Sn); 0.05-0.15% of titanium (Ti); 0.01% or less (excluding 0%) of sulfur (S); 0.005% or less (excluding 0%) of nitrogen (N); 0.05-0.15% of molybdenum (Mo); and the balance of iron (Fe) and inevitable impurities, and satisfies formula 1 and formula 2 below.

[Ni]/[Cu]≥0.5   [Formula 1]

48×([Ti]/48−[S]/32−[N]/14)≥0.04   [Formula 2]

Here, in formula 1 and formula 2, [Ni], [Cu], [Ti], [S], and [N] represent Ni, Cu, Ti, S, and N content (wt %) in the steel sheet, respectively.

The present invention provides a steel sheet having excellent wear resistance and composite corrosion resistance, and a method of manufacturing same. According to one example of the present invention, a corrosion-resistant steel sheet having excellent wear resistance and composite corrosion resistance comprises, in wt %: 0.04-0.10% of carbon (C); 0.10% or less (excluding 0%) of silicon (Si); 0.20-0.35% of copper (Cu); 0.1-0.2% of nickel (Ni); 0.05-0.15% of antimony (Sb); 0.07-0.22% of tin (Sn); 0.05-0.15% of titanium (Ti); 0.01% or less (excluding 0%) of sulfur (S); 0.005% or less (excluding 0%) of nitrogen (N); 0.05-0.15% of molybdenum (Mo); and the balance of iron (Fe) and inevitable impurities, and satisfies formula 1 and formula 2 below.

[Ni]/[Cu]≥0.5   [Formula 1]

48×([Ti]/48−[S]/32−[N]/14)≥0.04   [Formula 2]

Here, in formula 1 and formula 2, [Ni], [Cu], [Ti], [S], and [N] represent Ni, Cu, Ti, S, and N content (wt %) in the steel sheet, respectively.

Provided is a steel sheet which can be used for automobile parts and the like, and relates to a steel sheet having an excellent balance of strength and ductility and an excellent balance of strength and hole expansibility, and excellent bending workability, and a method for manufacturing same.

Provided is a steel sheet and a method for manufacturing same, the steel sheet, which can be used for automobile parts and the like, having superb bendability, and excellent balance of strength and ductility and of strength and hole expansion ratio. The steel sheet includes: by wt %, C: 0.25 to 0.75%, Si: 4.0% or less, Mn: 0.9 to 5.0%, Al: 5.0% or less, P: 0.15% or less, S: 0.03% or less, N: 0.03% or less, a balance of Fe, and unavoidable impurities; and as microstructures, ferrite which is a soft structure, and tempered martensite, bainite, and retained austenite which are hard structures.

Provided is a steel sheet and a method for manufacturing same, the steel sheet, which can be used for automobile parts and the like, having superb bendability, and excellent balance of strength and ductility and of strength and hole expansion ratio. The steel sheet includes: by wt %, C: 0.25 to 0.75%, Si: 4.0% or less, Mn: 0.9 to 5.0%, Al: 5.0% or less, P: 0.15% or less, S: 0.03% or less, N: 0.03% or less, a balance of Fe, and unavoidable impurities; and as microstructures, ferrite which is a soft structure, and tempered martensite, bainite, and retained austenite which are hard structures.