Patents Assigned to Sumitomo Metals (Kokura) Ltd.
  • Non-heat treated, soft-nitrided steel parts
    Patent number: 6391124
    Abstract: A non-heat treated soft-nitrided steel part respective contents of C, Si, Mn, P, Cr, Ti, V, N, Al, Pb, S and Ca of which are in specific ranges and which satisfies the following formulas (1) to (3). This part can be produced in a process of hot working, machining and soft-nitriding without any prior heat treatment, and has superior properties such as high fatigue strength and wear resistance. Fn1=−141.5(C %)−19.6(Mn %)+1280(N %)+95.6≦60  (1) Fn2=−103.8(C %)+59.1(Mn %)+850.4(N %)+360.9≧350  (2) Fn3=−13.4(C %)−3.45(Mn %)+112.7(N %)+13.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: May 21, 2002
    Assignees: Sumitomo Metals (Kokura) Ltd., Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Hitoshi Matsumoto, Yoshihiko Kamada, Mitsuo Uno, Masato Kurita, Seiichi Koike, Mitsuo Takashima