Metal treatment – Stock – Ferrous
Reexamination Certificate
2005-03-15
2005-03-15
Yee, Deborah (Department: 1742)
Metal treatment
Stock
Ferrous
C148S333000, C148S334000, C148S335000, C148S336000, C148S595000, C148S598000, C148S599000
Reexamination Certificate
active
06866724
ABSTRACT:
A bar or wire product for use in cold forging, characterized in that it comprises a steel having the chemical composition, in mass %: C: 0.1 to 0.6%, Si: 0.01 to 0.5%, Mn: 0.2 to 1.7%, S: 0.001 to 0.15%, Al: 0.015 to 0.05%, N: 0.003 to 0.025%, P: 0.035% or less, O: 0.003% or less and balance: Fe and inevitable impurities, and it has, in the region from the surface thereof to the depth of the radius thereof×0.15, a structure wherein ferrite accounts for 10 area % or less and the balance is substantially one or more of martensite, bainite and pearlite, and the average hardness in the region from the depth of the radius thereof×0.5 to the center thereof is less than that of the surface layer thereof by 20 or more of HV; and a method for producing the bar or wire product. The bar or wire product is excellent in the ductility after spheroidizing and thus allows the prevention of occurrence of cracks in a steel product during cold forging, which has conventionally been a problem in manufacturing structural parts for a machine by cold forging.
REFERENCES:
patent: 6602359 (2003-08-01), Ichi et al.
patent: 0 508 237 (1992-10-01), None
patent: 62-139817 (1987-06-01), None
patent: 7-34184 (1995-02-01), None
patent: 7-268546 (1995-10-01), None
patent: 9-287056 (1997-11-01), None
Toshizo Tarui, et al., “Chokusetsu Nanshitsuka Senzai no Kyoudo Ensei no oyobosu Goukin Genso no Eikyou”, Zairyou to Process, vol. 4 (1991) No. 3-2040.
Kanisawa Hideo
Naito Ken-ichiro
Ochi Tatsuro
Kenyon & Kenyon
Nippon Steel Corporation
Yee Deborah
LandOfFree
Steel bar or wire rod for cold forging and method of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Steel bar or wire rod for cold forging and method of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Steel bar or wire rod for cold forging and method of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3376778