Abstract: A steel powder composition useful in the production, by powder-metallurgical methods, of sintered parts with high density, good dimensional accuracy, hardenability, and strength is prepared from an admixture of two pre-alloyed iron powders of different compositions, the first being a pre-alloy of iron and molybdenum, and the second being a pre-alloy of iron with carbon and at least one transition element including chromium, manganese, vanadium, or columbium.

Abstract: A steel powder composition useful in the production, by powder-metallurgical methods, of sintered parts with high density, good dimensional accuracy, hardenability, and strength is prepared from an admixture of two pre-alloyed iron powders of different compositions, the first being a pre-alloy of iron and molybdenum, and the second being a pre-alloy of iron with carbon and at least one transition element including chromium, manganese, vanadium, or columbium.

Abstract: Methods for preparing sintered components from iron-containing and alloy steel powder are provided. The methods includes compacting a powder mixture in a die set at a pressure of at least about 25 tsi to produce a green compact which is then presintered at a temperature of about 1100.degree.-1600.degree. F. (593.degree.-870.degree. C.) for at least about 5 minutes to produce a presintered preform. The presintered preform is then compacted at a pressure of at least about 25 tsi to produce a double-pressed presintered preform, which is, in turn, sintered at a temperature of at least about 1000.degree. C. for at least about 5 minutes to produce a sintered component having improved transverse rupture strength and a higher density.

Abstract: In order to anneal high speed steel powder having a hardness of the order of about 550 to 600 Vickers and an oxygen content of 1500-2000 ppm, the powder is heated to a maximum temperature of about 1050.degree. C. and held at that temperature for about one hour. The powder is then gas quenched to between 700.degree. and 780.degree. C., held at that temperature for about one hour, and finally gas quenched to ambient temperature.

Abstract: A sieving device comprises a sieve with an electrical linear device mounted in spaced apart relation from the mesh of the sieve. Particles supplied to the side of the mesh away from the thrust device are caused by the thrust device to move across the mesh and those which are smaller than the mesh pass through the mesh and towards the thrust device. Conveniently a plate is disposed between the mesh and the plate. Particles passing through the mesh then come into contact with the plate and move along it under the influence of the thrust device.