Grain-oriented electrical steel sheet excellent in magnetic properties and adhesion of a primary coating to a base steel sheet and with few defects where the base metal is exposed in point defects and a method for manufacturing grain-oriented electrical steel sheet are provided. This is characterized by being provided with a base steel sheet and a primary coating. The primary coating satisfies (1) Number density D3 of Al concentrated regions: 0.015 to 0.150/μm.sup.2 (2) (Area S5 of regions comprised of anchoring oxide layer regions and Al concentrated regions)/(area S3 of Al concentrated regions)≥0.30, (3) Distance H5 of mean value of heights in thickness direction of regions of comprised of anchoring oxide layer regions and Al concentrated regions minus HO: 0.4 to 4.0 μm, (4) (Perimeter L5 of regions comprised of anchoring oxide layer regions and Al concentrated regions)/(observed area S0): 0.020 to 0.500 μm/μ.sup.2, and (5) (Area S1 of anchoring oxide layer regions)/(observed area S0)≥0.15.

Grain-oriented electrical steel sheet excellent in magnetic properties and adhesion of a primary coating to a base steel sheet and with few defects where the base metal is exposed in point defects and a method for manufacturing grain-oriented electrical steel sheet are provided. This is characterized by being provided with a base steel sheet and a primary coating. The primary coating satisfies (1) Number density D3 of Al concentrated regions: 0.015 to 0.150/μm.sup.2 (2) (Area S5 of regions comprised of anchoring oxide layer regions and Al concentrated regions)/(area S3 of Al concentrated regions)≥0.30, (3) Distance H5 of mean value of heights in thickness direction of regions of comprised of anchoring oxide layer regions and Al concentrated regions minus HO: 0.4 to 4.0 μm, (4) (Perimeter L5 of regions comprised of anchoring oxide layer regions and Al concentrated regions)/(observed area S0): 0.020 to 0.500 μm/μ.sup.2, and (5) (Area S1 of anchoring oxide layer regions)/(observed area S0)≥0.15.

A soft magnetic powder of the invention has a composition represented by Fe.sub.100-a-b-c-d-e-fCu.sub.aSi.sub.bB.sub.cM.sub.dM′.sub.eX.sub.f (at %) [wherein M is Nb, W, Ta, Zr, Hf, Ti, or Mo, M′ is V, Cr, Mn, Al, a platinum group element, Sc, Y, Au, Zn, Sn, or Re, X is C, P, Ge, Ga, Sb, In, Be, or As, and a, b, c, d, e, and f are numbers that satisfy the following formulae: 0.1≤a≤3, 0<b≤30, 0<c≤25, 5≤b+c≤30, 0.1≤d≤30, 0≤e≤10, and 0≤f≤10], wherein a crystalline structure having a particle diameter of 1 nm or more and 30 nm or less is contained in an amount of 40 vol % or more, and the difference in the coercive force of the powder after classification satisfies predetermined conditions.

A soft magnetic powder of the invention has a composition represented by Fe.sub.100-a-b-c-d-e-fCu.sub.aSi.sub.bB.sub.cM.sub.dM′.sub.eX.sub.f (at %) [wherein M is Nb, W, Ta, Zr, Hf, Ti, or Mo, M′ is V, Cr, Mn, Al, a platinum group element, Sc, Y, Au, Zn, Sn, or Re, X is C, P, Ge, Ga, Sb, In, Be, or As, and a, b, c, d, e, and f are numbers that satisfy the following formulae: 0.1≤a≤3, 0<b≤30, 0<c≤25, 5≤b+c≤30, 0.1≤d≤30, 0≤e≤10, and 0≤f≤10], wherein a crystalline structure having a particle diameter of 1 nm or more and 30 nm or less is contained in an amount of 40 vol % or more, and the difference in the coercive force of the powder after classification satisfies predetermined conditions.

The present disclosure relates to an iron-based prealloy powder having excellent strength and processability, and an iron-based alloy powder for powder metallurgy and a sinter-forged member using the same. The iron-based prealloy powder for powder metallurgy according to an embodiment of the present disclosure includes 0.5 to 5.0 wt % of Cu, 0.1 to 0.5 wt % of Mo, and a balance of Fe and other inevitable impurities. A Cu content (Cu %) and a Mo content (Mo %) satisfy the following Relational Equation (1):
0.3×Cu %+3×Mo %≤2.7  (1).

The present disclosure relates to an iron-based prealloy powder having excellent strength and processability, and an iron-based alloy powder for powder metallurgy and a sinter-forged member using the same. The iron-based prealloy powder for powder metallurgy according to an embodiment of the present disclosure includes 0.5 to 5.0 wt % of Cu, 0.1 to 0.5 wt % of Mo, and a balance of Fe and other inevitable impurities. A Cu content (Cu %) and a Mo content (Mo %) satisfy the following Relational Equation (1):
0.3×Cu %+3×Mo %≤2.7  (1).

The present invention provides a rare earth sintered magnet which contains R (R represents one or more rare earth elements essentially including Nd), T (T represents one or more iron group elements essentially including Fe), B, M.sup.1 (M.sup.1 represents one or more elements selected from among Al, Si, Cr, Mn, Cu, Zn, Ga, Ge, Mo, Sn, W, Pb and Bi) and M.sup.2 (M.sup.2 represents one or more elements selected from among Ti, V, Zr, Nb, Hf and Ta), while comprising an R.sub.2T.sub.14B phase as the main phase. This rare earth sintered magnet is characterized in that: the M.sup.1 is in an amount of from 0.5% by atom to 2% by atom; if (R), (T), (M.sup.2) and (B) are the respective atomic percentages of the above-described R, T, M.sup.2 and B, the relational expression (1) ((T)/14)+(M.sup.2)≤(B)≤((R)/2)+((M.sup.2)/2) is satisfied; and from 0.1% by volume to 10% by volume of all grain boundary phases in the magnet is composed of an R.sub.6T.sub.13M.sup.1 phase. This rare earth sintered magnet is able to achieve excellent magnetic characteristics including a good balance between high Br and high H.sub.cJ.

The present invention provides a rare earth sintered magnet which contains R (R represents one or more rare earth elements essentially including Nd), T (T represents one or more iron group elements essentially including Fe), B, M.sup.1 (M.sup.1 represents one or more elements selected from among Al, Si, Cr, Mn, Cu, Zn, Ga, Ge, Mo, Sn, W, Pb and Bi) and M.sup.2 (M.sup.2 represents one or more elements selected from among Ti, V, Zr, Nb, Hf and Ta), while comprising an R.sub.2T.sub.14B phase as the main phase. This rare earth sintered magnet is characterized in that: the M.sup.1 is in an amount of from 0.5% by atom to 2% by atom; if (R), (T), (M.sup.2) and (B) are the respective atomic percentages of the above-described R, T, M.sup.2 and B, the relational expression (1) ((T)/14)+(M.sup.2)≤(B)≤((R)/2)+((M.sup.2)/2) is satisfied; and from 0.1% by volume to 10% by volume of all grain boundary phases in the magnet is composed of an R.sub.6T.sub.13M.sup.1 phase. This rare earth sintered magnet is able to achieve excellent magnetic characteristics including a good balance between high Br and high H.sub.cJ.

An iron-based rare earth boron-based isotropic magnet alloy, which has an alloy composition represented by T.sub.100-x-y-z(B.sub.1-nC.sub.n).sub.xRE.sub.yM.sub.z (where T is a transition metal element containing at least Fe, RE contains at least Nd, and M is one or more metal elements selected from the group consisting of Al, Si, V, Cr, Ti, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au, and Pb), 4.2 atom %≤x≤5.6 atom %, 11.5 atom %≤y≤13.0 atom %, 0.0 atom %≤z≤5.0 atom %, and 0.0≤n≤0.5, and the iron-based rare earth boron-based isotropic magnet alloy has an average crystal grain size of 10 nm to less than 70 nm as a main phase.

An iron-based rare earth boron-based isotropic magnet alloy, which has an alloy composition represented by T.sub.100-x-y-z(B.sub.1-nC.sub.n).sub.xRE.sub.yM.sub.z (where T is a transition metal element containing at least Fe, RE contains at least Nd, and M is one or more metal elements selected from the group consisting of Al, Si, V, Cr, Ti, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au, and Pb), 4.2 atom %≤x≤5.6 atom %, 11.5 atom %≤y≤13.0 atom %, 0.0 atom %≤z≤5.0 atom %, and 0.0≤n≤0.5, and the iron-based rare earth boron-based isotropic magnet alloy has an average crystal grain size of 10 nm to less than 70 nm as a main phase.