A method for producing a NdFeB system sintered magnet. The method includes: a hydrogen pulverization process, in which coarse powder of a NdFeB system alloy is prepared by coarsely pulverizing a lump of NdFeB system alloy by making this lump occlude hydrogen; a fine pulverization process, in which fine powder is prepared by performing fine pulverization for further pulverizing the coarse powder; a filling process, in which the fine powder is put into a filling container; an orienting process, in which the fine powder in the filling container is oriented; and a sintering process, in which the fine powder after the orienting process is sintered as held in the filling container. The processes from hydrogen pulverization through orienting are performed with neither dehydrogenation heating nor evacuation each for desorbing hydrogen occluded in the hydrogen pulverization process. The processes from hydrogen pulverization through sintering are performed in an oxygen-free atmosphere.

A mold which is inexpensive and easy to process and does not embrittle. Also provided is a process by which a sintered NdFeB magnet can be produced using the mold without suffering bending or deformation. At least part (e.g., a bottom plate) of the mold is made of a carbon material. Carbon materials have lower friction with a sinter during sintering than metals. The mold hence enables a sintered NdFeB magnet to be produced without suffering the bending or deformation caused by friction due to sintering shrinkage. Carbon materials are inexpensive and easy to process. The mold does not embrittle even when repeatedly used. Such effects can be significantly produced when a carbon material is used as the bottom plate, on which the load of the sinter is imposed during sintering.

A mold which is inexpensive and easy to process and does not embrittle. Also provided is a process by which a sintered NdFeB magnet can be produced using the mold without suffering bending or deformation. At least part (e.g., a bottom plate) of the mold is made of a carbon material. Carbon materials have lower friction with a sinter during sintering than metals. The mold hence enables a sintered NdFeB magnet to be produced without suffering the bending or deformation caused by friction due to sintering shrinkage. Carbon materials are inexpensive and easy to process. The mold does not embrittle even when repeatedly used. Such effects can be significantly produced when a carbon material is used as the bottom plate, on which the load of the sinter is imposed during sintering.

The present invention relates to an additive manufacturing powder material including Fe alloy particles each having an oxide film on a surface thereof, in which the Fe alloy particles satisfy d≤15 and I/d≤0.025, where d [nm] represents a thickness of the oxide film, and a peak intensity ratio I represents an intensity ratio IB/IA of a peak B in a region B of a Raman shift of 1,309 to 1,329 cm.sup.−1 to a peak A in a region A of a Raman shift of 657.5 to 677.5 cm.sup.−1 in a Raman spectrum.

The present invention relates to an additive manufacturing powder material including Fe alloy particles each having an oxide film on a surface thereof, in which the Fe alloy particles satisfy d≤15 and I/d≤0.025, where d [nm] represents a thickness of the oxide film, and a peak intensity ratio I represents an intensity ratio IB/IA of a peak B in a region B of a Raman shift of 1,309 to 1,329 cm.sup.−1 to a peak A in a region A of a Raman shift of 657.5 to 677.5 cm.sup.−1 in a Raman spectrum.

A step of, while an RLM alloy powder (where RL is Nd and/or Pr; M is one or more elements selected from among Cu, Fe, Ga, Co, Ni and Al) and an RH oxide powder (where RH is Dy and/or Tb) are present on the surface of a sintered R-T-B based magnet, performing a heat treatment at a sintering temperature of the sintered R-T-B based magnet or lower is included. The RLM alloy contains RL in an amount of 50 at % or more, and the melting point of the RLM alloy is equal to or less than the temperature of the heat treatment. The heat treatment is performed while the RLM alloy powder and the RH oxide powder are present on the surface of the sintered R-T-B based magnet at a mass ratio of RLM alloy:RH oxide=9.6:0.4 to 5:5.

An R-TM-B hot-pressed and deformed magnet (here, R represents a rare earth metal selected from the group consisting of Nd, Dy, Pr, Tb, Ho, Sm, Sc, Y, La, Ce, Pm, Eu, Gd, Er, Tm, Yb, Lu, and a combination thereof, and TM represents a transition metal) of the present invention comprises flat type anisotropic magnetized crystal grains and a nonmagnetic alloy distributed in a boundary surface between the crystal grains, and thus the magnet of the present invention has an excellent magnetic shielding effect as compared with an existing permanent magnet since the crystal gains can be completely enclosed in the nonmagnetic alloy, so that a hot-pressed and deformed magnet with enhanced coercive force can be manufactured through a more economical process.

Disclosed is a high strength, high-temperature corrosion resistant martensitic stainless steel characterized by comprising the following chemical elements in percentages by mass: 0<C≤0.05%, 0.1-0.2% of Si, 0.20-1.0% of Mn, 11.0-14.0% of Cr, 4.0-6.0% of Ni, 1.5-2.5% of Mo, 0.001%-0.10% of N, 0.03-0.2% of V, 0.01-0.1% of Nb, 0.01-0.04% of Al, and the balance being Fe and inevitable impurities. In addition, also disclosed are tubing and casing manufactured from the above-mentioned high strength, high-temperature corrosion resistant martensitic stainless steel, and a method for manufacturing the tubing and the casing. The high strength, high-temperature corrosion resistant martensitic stainless steel of the present disclosure has an excellent high temperature corrosion resistance to carbon dioxide and chloride ions, as well as excellent low-temperature impact toughness and a high-temperature strength degradation resistance.

One embodiment of the present invention provides a polymeric ammunition having a metal injection molded primer insert.

There is provided a compact for a magnet which can produce a magnetic member having high coercive force. The compact for a magnet is produced by compression-molding a rare earth-iron-based alloy powder containing a plurality of particles of a rare earth-iron-based alloy containing a rare earth element and iron, wherein the rare earth-iron-based alloy satisfies configurations (a) to (c) below and has 5% by volume or more and 20% by volume or less of voids formed therein. (a) Having a structure containing 10% by mass or more and 30% by mass or less of Sm, 10% by mass or less of Mn, and the balance consisting of Fe and inevitable impurities. (b) A composition, Sm.sub.2MN.sub.xFe.sub.17-x (x=0.1 or more and 2.5 or less). (c) An average crystal grain diameter of 700 nm or less.