Aichi Steel Works, Ltd.

Aichi Steel Work, Ltd.

Kouji Murata

Yoshinobu Honkura

Toru Matsuo

Takashi Yokoyama

Yoshihiro Nakashima

Chisato Mishima

Takenobu Yoshimatsu

Mitsuyuki Maeda

Kenichi Kumagai

An apparatus that gives continuous hydrogen heat treatment to anisotropic rare earth magnet powders is invented. The apparatus a comprises shopper 12, a furnace 11 to carry out a hydrogen heat treatment, a heat compensating means 14 that is placed in the heating room of the furnace to keep the treatment temperature constant, a movable stopper 15 to support the material in the heating room of the furnace 11 and a cooling container 18. The raw magnet powder is fed into the furnace 11 and supported by the stopper 15, then hydrogen heat treatment is carried out. After the treatment the stopper opens the bottom end of the heating room and the processed magnet powder falls into the cooling room. By the operation described above, the present apparatus can carry out continuous hydrogen heat treatment without stopping the heating of the furnace batch by batch. Continuous hydrogen heat treatment greatly improves the production efficiency and quality of the processed magnet powder.

Production apparatus for rare earth anisotropic magnet powders

A high strength non-magnetic stainless steel comprising, by weight ratio, less than 0.20% C, less than 1.00% Si, 14-16% Mn, less than 0.005% S, 0.2-1.0% Ni, 15-19% Cr, 0.30-0.40% N, and Fe and other impurity elements, of which C+N constitutes 0.40-0.55% and the Mn equivalent equals 30-33. The stainless steel has a hardness more than Hv 500, a magnetic permeability less than 1.01 after drawing, the steel may be suitably used as the steel for the micro shafts of video tape recorders and electromagnetic valves.

Method for manufacturing high strength non-magnetic stainless steel

As for high strength stainless steels and method for manufacturing the high strength stainless steels, the strength of the stainless steels are enhanced by adding an appropriate amount of both nitrogen and niobium to austenitic stainless steels, inhibiting boron, an impure element, and decreasing the carbon content. The strength of the stainless steels are further enhanced by such heat treatment as control rolling and low temperature solution heat treatment applied to the stainless steels after the control rolling.

High strength hot worked stainless steel

Method for manufacturing a high strength stainless steel

A high strength non-magnetic stainless steel comprising by weight ratio, less than 0.20 % C, less than 1.00 % Si, 14-16 % Mn, less than 0.005 % S, 0.2-1.0 % Ni, 15-19 % Cr, 0.30-0.40 % N, and Fe and other impurity elements, of which C+N constitutes 0.40-0.55 % and the Mn equivalent equals 30-33. The stainless steel has a hardness more than Hv 500, a magnetic permeability less than 1.01 after drawing, the steel may be suitably used as the steel for the micro shafts of video tape recorders and electromagnetic valves.

High strength non-magnetic stainless steel

Stainless steels possessing a superior cold workability and hot workability, which are yet economical. The stainless steels comprise not more than 0.04% carbon, not more than 0.60% silicon, 2.2-3.8% manganese, 2.5-4.0% copper, 6-8% nickel, 17-19% chromium, and the remainder being iron together with impurities. And, not more than 0.002% sulfur is decreased to provide stainless steels which possess superior corrosion resistance, and not more than 0.010% nitrogen are decreased in the stainless steels as required.

Cold working stainless steel

A soft magnetic stainless steel consists essentially of, by weight, up to 0.03% of C, 0.40 to 1.10% of Si, up to 0.50% of Mn, 9.0 to 19.0% of Cr, 0.31 to 0.60% of Al, 0.01 to 0.03% of S, 0.10 to 0.30% of Pb, 0.02 to 0.25% of Ti, 0.02 to 0.10% of Zr, and up to 0.03% of N, and the balance of Fe and inevitable impurities, with a proviso that the C+N content is not more than 0.04% and the Si+Al content is not more than 1.35%. The steel has a magnetic flux density of 13,000 G or more and a coercive force of 1.2 Oe or less as magnetic properties, and a tensile strength of 41 kgf/mm.sup.2 or less and a critical compressibility of 50% or more as formability in cold forging. The steel is suitable for manufacturing, by cold forging, parts with complex shapes such as cores of solenoid operated valves and electromagnetic clutches, and bodies of electronic fuel injection apparatuses for internal combustion engines.

Soft magnetic stainless steel for cold forging

A soft magnetic stainless steel consisting essentially of, by weight, up to 0.03% of C, 2.0 to 3.0% of Si, up to 0.40% of Mn, 0.015 to 0.050% of S, 10 to 13% of Cr, 0.05 to 0.20% of Ti, up to 0.03% of N, up to 0.010% of Al, and the balance of Fe and inevitable impurities, with a proviso that the C+N content is not more than 0.05%. The steel has a maximum permeability of not less than 4400 and a magnetic flux density of not less than 12,000 G as magnetic properties, together with a fatigue strength after welding of not lower than 120 kgf cm.sup.2, retains the magnetic properties even after annealing at a high temperature of 920.degree. C., and is excellent in electrical resistance, corrosion resistance, mechanical properties and machinability.

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Tokai, Japan

Kouji Murata