| 摘要 |
PURPOSE:To produce powder metal forged parts having excellent hardenability and toughness at los cost by using the Cr-Mn low alloy powder of ultra low oxygen produced by an oil spraying method as a raw material for the powder metal forged parts. CONSTITUTION:The melt of inexpensive Cr-Mn low alloy steel having excellent hardenability is pulverized in an oxidation-free state by an oil spraying method using nonpolar solvents mineral oils, vegetable oils, etc. After such Cr-Mn low alloy steel powder is degreased, oxide powder of Cr-Mn low alloy steel is added as a decarburizer and a small amt. of lead stearate is added as a lubricant thereto and these materials are thoroughly mixed and molded under pressure, whereby green compacts are produced. The green compacts are heated and sintered in an inert gaseous atmosphere and during the course thereof, the raw material powder steel is decarburized by oxides and is then hot-forged, whereby the powder metal forged parts which contain extremely less oxygen, and have excellent roughness and hardenability are produced inexpensively. |
