A stainless steel seamless pipe having high strength and excellent corrosion resistance. The stainless steel seamless pipe has a specified composition in which C, Si, Mn, Cr, Ni, Mo, Cu, and N satisfy a predetermined formula, a microstructure containing at least 25% martensitic phase, at most 65% ferrite phase, and at most 40% retained austenite phase by volume, and a yield strength of 758 MPa or more.

Provided is a high strength steel sheet that has a predetermined chemical composition and is manufactured under optimum conditions, the high strength steel sheet having a steel microstructure including, by area, ferrite: 30% or more and 80% or less, tempered martensite: 3.0% or more and 35% or less, and retained austenite: 8% or more, wherein the quotient of the area fraction of grains of the retained austenite, the grains having an aspect ratio of 2.0 or more and a minor axis length of 1 μm or less, divided by the total area fraction of the retained austenite is 0.3 or more, wherein the quotient of the average Mn content (mass %) in the retained austenite divided by the average Mn content (mass %) in the ferrite is 1.5 or more.

A neodymium-iron-boron magnetic material, a preparation method therefor and an application thereof. The neodymium-iron-boron magnetic material comprises the following components in percentage by mass: 29.5-31.5 wt. % of R, where RH>1.5 wt. %; 0.05-0.25 wt. % of Cu; 0.42-2.6 wt. % of Co; 0.20-0.3 wt. % of Ga; 0.25-0.3 wt. % of N; 0.46-0.6 wt. % of Al, or alternatively Al is less than or equal to 0.04 wt. % but is not 0; 0.98-1 wt. % of B; and 64-68 wt. % of Fe; wherein R is a rare-earth element and comprises Nd and RH, RH is a heavy rare-earth element and comprises Tb, and a mass ratio of Tb to Co is less than or equal to 15 but is not 0. The neodymium-iron-boron magnetic material has higher Hcj and Br, and lower absolute values of temperature coefficients of Br and Hcj.

An austenitic stainless steel flux cored wire may provide a welded metal having excellent cryogenic temperature toughness; a welded metal from the wire may have excellent cryogenic temperature toughness; and a welding method may involve such wire(s). An austenitic stainless steel flux cored wire in which a flux is filled in a steel-made shell. The flux cored wire may contain Si, Mn, Ni, Cr, C, P, and N in amounts each falling within a specified range relative to the entire mass of the wire, with the remainder made up by Fe and unavoidable impurities, and X.sub.1 is 17.5 to 22.0 inclusive, as calculated by formula (1):

X.sub.1=[Ni].sub.W+0.5×[Cr].sub.W+1.6×[Mn].sub.W+0.5×[Si].sub.W+15×[C].sub.W  (1),

wherein, in formula (1), [Ni].sub.W, [Cr].sub.W, [Mn].sub.W, [Si].sub.W and [C].sub.W represent the contents (% by mass) of Ni, Cr, Mn, Si, and C, relative to the entire mass of the wire.

Provided is a non-oriented electrical steel sheet having an average crystal grain size of crystal grains being not more than 80 μm, an area ratio of crystal grains having a grain size of not less than 1.5 times the average crystal grain size being not less than 10%; and an area ratio of crystal grains having aspect ratios of not more than 0.3 being not more than 20%, by subjecting a steel raw material containing, in mass %, C: not more than 0.005%, Si: 2.0 to 5.0%, Mn: 0.05 to 5.0%, Al: not more than 3.0%, and Zn: 0.0003 to 0.0050% to hot rolling, cold rolling, and cold-rolled sheet annealing and by heating the cold-rolled sheet to an annealing temperature between 700 to 850° C. at the average heating rate between 500 and 700° C. in a heating process of the cold-rolled sheet annealing to be not less than 10° C./s.

The present disclosure relates to a high-chromium white iron alloy comprising rare-earth (RE) element. The alloy comprises RE of 0.01-0.6 wt %, Cr of 26-30 wt %, C of 2.5-4 wt %, Si of 0.2-2 wt %, Mn of 0.5-1 wt %, Mo of 0.2-0.5 wt %, Ni of 0.01-0.6 wt %, at most 1 wt % of impurities, and a balance of Fe. The invention also relates to a white iron product made from the alloy. Further, the invention relates to a method comprising adding an RE powder to a metal melt comprising Cr, C, Si, Mn, Mo, Ni and Fe as above, whereby a white iron alloy melt comprising RE is formed.

A steel sheet has a predetermined chemical composition and a metal structure represented by, in area fraction, polygonal ferrite: 40% or less, martensite: 20% or less, bainitic ferrite: 50% to 95%, and retained austenite: 5% to 50%. In area fraction, 80% or more of the bainitic ferrite is composed of bainitic ferrite grains that have an aspect ratio of 0.1 to 1.0 and have a dislocation density of 8×10.sup.2 (cm/cm.sup.3) or less in a region surrounded by a grain boundary with a misorientation angle of 15° or more. In area fraction, 80% or more of the retained austenite is composed of retained austenite grains that have an aspect ratio of 0.1 to 1.0, have a major axis length of 1.0 μm to 28.0 μm, and have a minor axis length of 0.1 μm to 2.8 μm.

The present invention discloses rare earth-bonded magnetic powder and a preparation method therefor. The bonded magnetic powder is of a multilayer core-shell structure, and comprises a core layer and an antioxidant layer (3), wherein the core layer is formed by RFeMB, R is Nd and/or PrNd, and M is one or more of Co, Nb, and Zr; and the core layer is coated with an iron-nitrogen layer (2). In addition, the present invention also discloses the preparation method for the rare earth-bonded magnetic powder and a bonded magnet. The oxidation and corrosion of magnetic raw powder during phosphorization and subsequent treatment process are effectively prevented, thereby further improving the long-term temperature resistance and environmental tolerance of the material.

A high-strength steel sheet has a specific composition and a microstructure. In the microstructure, the area fraction of elongated ferrite phase grains having an aspect ratio of 3 or more is 1% or less, the average crystal grain size of martensite included in a region extending 50 μm from a surface of the steel sheet is 20 μm or less, the content of oxide particles having a minor axis length of 0.8 μm or less in the region extending 50 μm from the surface of the steel sheet is 1.0×10.sup.10 particles/m.sup.2 or more, and the content of coarse oxide particles having a minor axis length of more than 1 μm in the region extending 50 μm from the surface of the steel sheet is 1.0×10.sup.8 particles/m.sup.2 or less. The content of hydrogen trapped in the steel sheet is 0.05 ppm by mass or more.

A method of preparing magnetic powder includes preparing iron powder by a reduction reaction of iron oxide; preparing magnetic powder by heat-treating a molded article prepared by pressure-molding a mixture containing the iron powder, neodymium oxide, boron and calcium at a pressure of 22 MPa or more; and coating an organic fluoride on a surface of the magnetic powder.