Nagoya, Japan
Nagoya, Japan

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Patent
Daido Steel Co. | Date: 2017-03-01

The present invention relates to a steel and a mold constituted of the steel, in which the steel contains as essential elements, in terms of % by mass, 0.58%C0.70%, 0.010%Si0.30%, 0.50%Mn2.00%, 0.50%Cr<2.0%, 1.8%Mo3.0%, and 0.050%


Patent
Daido Steel Co. and Denso Corporation | Date: 2017-01-11

The present invention provides an age hardening type bainitic microalloyed steel having a composition which includes, in terms of mass%: 0.06-0.35% of C; 0.01-2.00% of Si; 0.10-3.00% of Mn; 0.001-0.200% of S; 0.001-2.00% of Cu; 0.40-3.00% of Ni; 0.10-3.00% of Cr; 0.10-1.00% of Mo; 0.10-1.00% of V; and 0.001-0.100% of s-Al, with the remainder being Fe and unavoidable impurities, and which satisfies a value of the following expression (1) to be 20 or larger and a value of the following expression (2) to be 0.82 or larger:


Patent
Intermetallics Co. and Daido Steel Co. | Date: 2017-04-05

The purpose of the present invention is to provide an RFeB system sintered magnet which has a high and uniform level of coercivity over the entirety of the single magnet even if the magnet is comparatively thick. The present invention is an RFeB system sintered magnet in which a heavy rare-earth element R^(H) which is at least one kind of rare-earth element selected from the group of Dy, Tb and Ho is diffused into a base material through the grain boundaries of the same base material made of a sintered compact of an RFeB system magnet containing R^(L), Fe and B, where R^(L) represents a light rare-earth element which is at least one kind of rare-earth element selected from the group of Nd and Pr, wherein: the size of the RFeB system sintered magnet at a smallest-size portion is greater than 3 mm; the amount of heavy rare-earth element R^(H) contained in the RFeB system sintered magnet divided by the volume of the RFeB system sintered magnet is equal to or greater than 25 mg/cm^(3); and the difference between a local coercivity at the surface of the smallest-size portion and a local coercivity in the central region of the smallest-size portion is equal to or less than 15 % of the local coercivity at the surface.


The present invention relates to a part obtained from an age hardening type bainitic microalloyed steel, a process for producing the part, and the age hardening type bainitic microalloyed steel. In particular, the present invention relates to a part which has been controlled so as to have higher values of strength than conventional parts, a process for producing the part, and the age hardening type bainitic microalloyed steel.


Patent
Intermetallics Co. and Daido Steel Co. | Date: 2016-01-27

The present invention addresses the problem of providing a method for easily producing an RFeB system sintered magnet having high coercivity and being capable of suppressing the influence of eddy current during a period of use while being composed of a plurality of unit sintered magnets strongly bonded together. It is a method for producing an RFeB system sintered magnet composed of at least two unit sintered magnets 11 bonded to each other at flat bonding surfaces, each unit sintered magnet composed of crystal grains whose main phase is made of R_(2)Fe_(14)B containing, as a main rare-earth element R, a light rare-earth element R_(L) which is at least one element selected from the group of Nd and Pr. A paste 12 prepared by mixing an organic matter and a metallic powder containing at least one element selected from the heavy rare-earth elements R_(H) of Dy, Ho and Tb is sandwiched between the mutually neighboring unit sintered magnets 11, and a grain boundary diffusion treatment is performed by performing a heating process, with the paste 12 in contact with each bonding surface. The coercivity is improved by this grain boundary diffusion treatment. Furthermore, since an oxide or similar compound of R_(H) and/or R_(L) is formed at the boundary of the unit sintered magnets 11, the influence of eddy current during a period of use is suppressed, and the unit sintered magnets 11 are strongly bonded together.


Patent
Intermetallics Co. and Daido Steel Co. | Date: 2016-05-31

A powder-filling system capable of filling a container with powder at an approximately uniform filling density has: a hopper having an opening removably and hermetically closably attached to the container, the hopper communicating with the container at the opening for supplying powder to a container; a powder supplier for supplying powder to the hopper; a gas supplier for repeatedly supplying compressed gas in a pulsed form to the hopper, with the hopper hermetically closably attached to the container; and a sieve member provided at the opening and having a smaller openings in a region near a side wall of the hopper than in its central region. The smaller openings in the region near the side wall of the hopper where the powder more easily falls from the hopper into the container impedes the fall of the powder in that region and improves the overall uniformity in the filling density.


The present invention addresses the problem of providing a method for producing an RFeB system magnet with high coercivity by preventing a coating material from peeling off the surface of a base material during a grain boundary diffusion treatment. Provided is a method for producing an R^(L)_(2)Fe_(14)B system magnet which is a sintered magnet or a hot-deformed magnet containing, as the main rare-earth element, a light rare-earth element R^(L) which is at least one of the two elements ofNd and Pr, the method including the steps of: applying, to a surface of a base material M of the R^(L)_(2)Fe_(14)B system magnet, a coating material 10 prepared by mixing a silicone grease 11 and an R^(H)-containing powder 14 containing a heavy rare-earth element R^(H) composed of at least one element selected from the group of Dy, Tb and Ho; and heating the base material M together with the coating material. The silicone having a siloxane bond prevents the coating material 10 from peeling off the surface of the base material M during the heating process. The improved adhesion of the coating material 10 to the base material M facilitates transfer of R^(H) into the grain boundaries of the base material M, whereby the coercivity is increased.


Patent
Daido Steel Co. | Date: 2016-07-20

The present invention relates to a method for manufacturing a sintered magnet, using a mold provided with a main body having a cavity and a lid whose inner face is flat, and the method containing a filling process of filling alloy powder in the cavity and then mounting the lid on the main body, an orienting process of applying a magnetic field in a predetermined direction to the alloy powder in a state of being filled in the cavity, a sintering process of sintering the alloy povvder by heating in a state of being filled in the cavity after the orienting process, and a mold inverting process of turning the mold upside down which is carried out between the filling process and the orienting process or between the orienting process and the sintering process


Patent
Daido Steel Co. | Date: 2016-11-23

The present invention relates to a maraging steel containing, in terms of mass%, 0.10 C 0.35, 9.0 Co 20.0, 1.0 (Mo + W/2) 2.0, 1.0 Cr 4.0, a certain amount ofNi, a certain amount of A1, and V + Nb 0.60, with the balance being Fe and inevitable impurities, in which in a case of V + Nb 0.020, the amount of Ni is 6.0 Ni 9.4 and the amount of Al is 1.4 A1 2.0, and in a case of 0.020 < V + Nb 0.60, the amount ofNi is 6.0 Ni 20.0 and the amount of Al is 0.50 A1 2.0.


The present invention relates to an exhaust valve of a diesel engine for a large ship, containing a shaft part and an umbrella part that are integrated with each other and made of an Ni-Cr-Al system Ni-base age-precipitated alloy, in which the exhaust valve has a layered structure and hardness of 600 HV or less as a whole, and the layered structure contains a layer formed of an -Cr phase having a thickness of 150 nm or more that is aged beyond peak mechanical strength.

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