Disclosed in the present invention are a heavy rare earth alloy, neodymium-iron-boron permanent magnet material, a raw material, and a preparation method. The heavy rare earth alloy comprises the following components: RH: 30-100 mas %, not including 100 mas %; X, 0-20 mas %, not including 0; B: 0-1.1 mas %; and Fe and/or Co: 15-69 mas %, RH comprising one or more heavy rare earth elements in Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc, and X being Ti and/or Zr. When the heavy rare earth alloy of the present invention is used as a sub-alloy to prepare the neodymium-iron-boron permanent magnet material, a high utilization rate of heavy rare earth is achieved, so that the coercivity can also be greatly improved while the neodymium-iron-boron permanent magnet material maintains high remanence.

A method for manufacturing a non-oriented electrical steel sheet includes a step of obtaining a hot-rolled steel sheet by performing hot rolling on a steel material having a predetermined chemical composition, a step of performing first cold rolling on the hot-rolled steel sheet, and a step of performing first annealing after the first cold rolling. A final pass of finish rolling is performed in a temperature range equal to or higher than an Ar1 temperature, and cooling of which an average cooling rate is in a range of 50 to 500° C./sec is started in 0.1 sec from completion of rolling of the final pass of the finish rolling and is performed up to a temperature range higher than 250° C. and equal to or lower than 700° C.

A method for manufacturing a non-oriented electrical steel sheet includes a step of obtaining a hot-rolled steel sheet by performing hot rolling on a steel material having a predetermined chemical composition, a step of performing first cold rolling on the hot-rolled steel sheet, and a step of performing first annealing after the first cold rolling. A final pass of finish rolling is performed in a temperature range equal to or higher than an Ar1 temperature, and cooling of which an average cooling rate is in a range of 50 to 500° C./sec is started in 0.1 sec from completion of rolling of the final pass of the finish rolling and is performed up to a temperature range higher than 250° C. and equal to or lower than 700° C.

A hot-dip zinc-plated steel sheet includes a steel sheet, a boundary layer that is provided on a surface of the steel sheet, and a hot-dip zinc-plated layer that is provided on a surface of the boundary layer. In a surface layer region of the steel sheet, an average grain size is 4.0 μm or less and a standard deviation of grain sizes is 2.0 μm or less. In the boundary layer, a maximum Al concentration is 0.30 mass % or more.

A hot-dip zinc-plated steel sheet includes a steel sheet, a boundary layer that is provided on a surface of the steel sheet, and a hot-dip zinc-plated layer that is provided on a surface of the boundary layer. In a surface layer region of the steel sheet, an average grain size is 4.0 μm or less and a standard deviation of grain sizes is 2.0 μm or less. In the boundary layer, a maximum Al concentration is 0.30 mass % or more.

A composite material includes: an iron-based alloy layer; an intermediate layer provided on the iron-based alloy layer; and a tungsten-containing layer provided on the intermediate layer, wherein the intermediate layer is composed of pure nickel or is an alloy that contains at least one selected from a group consisting of copper, cobalt, and iron at more than 0 mass % and less than or equal to 71 mass % in total, and that contains nickel at more than or equal to 29 mass % and less than 100 mass %.

An R-T-B series permanent magnet material, a raw material composition, a preparation method, and an application. The R-T-B series permanent magnet material comprises the following components: R: 29-31.0 wt. %, RH is greater than 1 wt. %, B: 0.905-0.945 wt. %, C: 0.04-0.15 wt. %, N: 0.1-0.4 wt. %, and Fe: 67-69 wt. %, wherein R comprises RL and RH, RL is a light rare earth element, RL comprises Nd, RH is a heavy rare earth element, a (RL.sub.1-yRH.sub.y).sub.2T.sub.17C.sub.x phase is present at the grain boundary of the R-T-B series permanent magnet material, x: 2-3, y: 0.15-0.35, and T must comprise Fe, and also comprises one or more among Co, Ti and N. The permanent magnet material retains relative high Br and Hcj under different heat treatment temperatures.

An R-T-B series permanent magnet material, a raw material composition, a preparation method, and an application. The R-T-B series permanent magnet material comprises the following components: R: 29-31.0 wt. %, RH is greater than 1 wt. %, B: 0.905-0.945 wt. %, C: 0.04-0.15 wt. %, N: 0.1-0.4 wt. %, and Fe: 67-69 wt. %, wherein R comprises RL and RH, RL is a light rare earth element, RL comprises Nd, RH is a heavy rare earth element, a (RL.sub.1-yRH.sub.y).sub.2T.sub.17C.sub.x phase is present at the grain boundary of the R-T-B series permanent magnet material, x: 2-3, y: 0.15-0.35, and T must comprise Fe, and also comprises one or more among Co, Ti and N. The permanent magnet material retains relative high Br and Hcj under different heat treatment temperatures.

A high-strength cold-rolled steel sheet having a high yield ratio and excellent stretch flangeability and a method for manufacturing the steel sheet. The high-strength cold-rolled steel sheet has a chemical composition including, by mass %, C: 0.10 to 0.30%, Si: 0.50 to 2.00%, Mn: 2.5 to 4.0%, P: 0.050% or less, S: 0.020% or less, Al: 0.10% or less, N: 0.01% or less, Ti: 0.100% or less, and B: 0.0003 to 0.0030%, with the balance being Fe and incidental impurities. N and Ti satisfy a specified formula, and the total area fraction of martensite and bainite is 95% or more. The number density of bainite grains having an area of 3 μm.sup.2 or more and a carbon concentration of less than 0.7C is 1200 grains/mm.sup.2 or less.

A high-strength cold-rolled steel sheet having a high yield ratio and excellent stretch flangeability and a method for manufacturing the steel sheet. The high-strength cold-rolled steel sheet has a chemical composition including, by mass %, C: 0.10 to 0.30%, Si: 0.50 to 2.00%, Mn: 2.5 to 4.0%, P: 0.050% or less, S: 0.020% or less, Al: 0.10% or less, N: 0.01% or less, Ti: 0.100% or less, and B: 0.0003 to 0.0030%, with the balance being Fe and incidental impurities. N and Ti satisfy a specified formula, and the total area fraction of martensite and bainite is 95% or more. The number density of bainite grains having an area of 3 μm.sup.2 or more and a carbon concentration of less than 0.7C is 1200 grains/mm.sup.2 or less.