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
10811274
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.
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Hirano Kenji
Ueda Masami
Jordan and Hamburg LLP
King Roy
Morillo Janelle
Neomax Materials Co., Ltd.
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