Metal treatment – Process of modifying or maintaining internal physical... – With casting or solidifying from melt
Reexamination Certificate
2008-01-29
2008-01-29
King, Roy (Department: 1742)
Metal treatment
Process of modifying or maintaining internal physical...
With casting or solidifying from melt
C148S548000, C148S621000, C148S624000
Reexamination Certificate
active
07323070
ABSTRACT:
A process of producing a maraging steel includes melting a steel of a defined composition, casting the molten steel to obtain a steel ingot, hot forging the steel ingot at a forging ratio of at least 4, then soaking the forged piece one or more times to keep the forged piece in a temperature range of 1100-1280° C. for 10-100 hours, and then plastic working the forged piece. A process of producing a maraging steel of another defined composition includes casting the molten steel to obtain a steel ingot with a defined taper, a defined height to diameter ratio and a defined flatness ratio and plastic working the steel ingot so that the size of a nonmetallic inclusion is 30 μm or less expressed as the diameter of a circle of circumference equal to the perimeter (“circumference”) of the inclusion.
REFERENCES:
patent: 3532491 (1970-10-01), Floreen et al.
patent: 49-9465 (1974-01-01), None
patent: 49009465 (1974-01-01), None
patent: 59-147746 (1984-08-01), None
patent: 1-142022 (1989-06-01), None
patent: 2-163315 (1990-06-01), None
patent: 6-248389 (1994-09-01), None
patent: 8-269564 (1996-10-01), None
patent: 10-30107 (1998-02-01), None
patent: 10-193038 (1998-07-01), None
patent: 11-074807 (1999-03-01), None
patent: 11-239146 (1999-08-01), None
patent: 11-293407 (1999-10-01), None
“Metals Handbook: vol. 1 Properties and Selection: Irons, Steels, and High-Performance Alloys”, ASM International, 1990, p. 793-800.
Recent Developments in Specialized Smelting Technology, Chapter 7, Specialized Meltig Techniques by Kishida, Tamiya, The Iron and Steel Institute of Japan (Nippon Tokko Kyokai) Feb. 17, 18, 1981(72nd meeting); Mar. 11, 12, 1981(73rd meeting) 207-208.
Nov. 7, 1967 “The Origin and Significance of Banding in 18Ni (250) Maraging Steel” P.H. Salmon Cox, B.G. Reisdorf, and G.E. Pellissier, Transactions of the Metallurgical Society of AIME 239 1809-1817.
Jul. 31, 2001 Notice of Revocation of the Japanese Patent No. 3110733.
Jul. 31, 2001 Notice of Revocation of the Japanese Patent No. 3110726.
Hirano Kenji
Ueda Masami
Jordan and Hamburg LLP
King Roy
Morillo Janelle
Neomax Materials Co., Ltd.
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