| 摘要 |
<p>High-strength and high-toughness sintered alloy steel and composite alloy steel powder for use in production of the steel are disclosed. The steel contains as final product alloy components Ni, Mo and/or W and, if necessary, C with the content of Ni being 0.50 to 3.50 wt %, the content of Mo+1/2W being 0.65 to 3.50 wt % and, if necessary, the content of C being 0.3 to 0.8 wt %, and the balance being Fe and unavoidable impurities, and has a density of at least 7.0 g/cm3 and a tensile strength of at least 130 kgf/mm2. The content of each of Ni and Mo+1/2W in the alloy steel powder of a particle size of 45 νm or less are 2.0 to 4.2 times as much as the average content of the whole powder. This composition gives high-strength and high-toughness sintered alloy steel by powder metallurgy using a comparatively low alloy formulation and heat-treated sintered steel satisfying requirements for automobile parts, etc.</p> |
