Mitsubishi Steel Mfg. Co., Ltd.

Hitachi Powdered Metals Co., Ltd.

Yukio Tokuyama

Yuji Soda

Kei Ishii

Yoshimasa Aoki

Hiroshi Usui

A water-atomized metal powder having a spherical particle shape, an average particle size of 25 &mgr;m or less and a tap density ratio of 50-60%. The spherical powder is produced by forming non-spherical metal particles, which have been produced from molten metal by water-atomization, into spherical particles using a high speed gas current which causes high speed collisions to occur between said particles and between said particles and a collision body. The thus obtained spherical metal powder is particularly suitable for injection molding since and, by using the powder, the blending proportion of organic binder used in injection molding can be reduced and high strength debound bodies can be obtained.

Water-atomized spherical metal powders and method for producing the same

A source powder for a wear-resistant sintered material, consisting essentially of, in weight percentages, Cr: 3.0 to 6.0%, 2 Mo+W: 10.0 to 20.0%, V: 1.0 to 8.0%, Co: 10.0% or below, C: 0.20% to {0.01(2 Mo+W)+0.24 V}%, Si: 0.1 to 1.0%, Mn: 0.1 to 1.0% and the balance being Fe and unavoidable impurities, or one prepared by adding 0.10 to 0.8% of S to the above composition. This powder can be compacted into a green compact having a high green density, which can further give a wear-resistant sintered material having a high sintered density, hardness and strength.

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Chiba, Japan

Yukio Tokuyama