Abstract: A mixture for a powder metallurgy product, including iron powder, graphite powder and copper (Cu) of about 3.0 to about 5.0 weight percent. Iron powder includes iron grains which contain MnS therein. The mixture contains the MnS of about 0.65 to about 1.40 weight percent. The graphite powder is contained in the mixture such that an amount of carbon (C) in the powder metallurgy product is about 0.3 to about 0.7 weight percent. An amount (wt % C) of the carbon and an amount (wt % Cu) of the copper is determined to obtain a target fatigue strength FS (MPa) and a target hardness HR (HRB) based on a relation
FS=66.63×(wt % C)+22.61×(wt % Cu)+280.84
HR=22.96×(wt % C)+2.99×(wt % Cu)+78.91.
Type:
Grant
Filed:
November 9, 2000
Date of Patent:
May 21, 2002
Assignees:
Kobeico Metal Powder of America, Inc., Kobe Steel, Ltd., Honda Giken Kogyo Kabushiki Kaisha
Inventors:
Nobuaki Akagi, Shinya Kawai, Masaaki Satoh, Yoshikazu Seki, Masaki Amano, Hideaki Ushio, Russell T. Scott