Leland Stanford Junior University

Lockheed Missiles & Space Company, Inc.

Sptek

Jeffrey Wadsworth

Oleg D Sherby

Toshimasa Oyama

Donald D Crooks

Richard E Lewis

Dong W Kum

Aldo E Vidoz

Ian G Palmer

Oscar Ruano

An ultrahigh carbon steel having a composition of carbon in an amount of from about 0.8 weight percent up to the maximum solubility limit of carbon in austenite, aluminum in an amount of from about 0.5 to about 10 weight percent, an effective amount of a stabilizing element acting to stabilize iron carbide against graphitization, and the balance iron. Preferably, the aluminum is present in an amount of from about 0.5 to about 6.4 weight percent and the stabilizing element is chromium. The steel has excellent ductility and is readily hot, warm and cold worked without cracking. It is particularly useful in superplastic forming operations, and may be processed to a suitable microstructure by any technique which reduces its grain size to about 10 microns or less, and preferably to about 1 micron. Such a very fine grain size is readily acheived with the steel, and the aluminum and stabilizing additions act to retain the fine grain size during superplastic processing.

Ultrahigh carbon steels containing aluminum

Aluminum base alloys characterized by low density, high elastic modulus and high strength and having a composition consisting esentially of aluminum--about 0.5 to about 4.3 weight percent lithium--about 0.02 to about 20 weight percent beryllium.

Aluminum base alloys

A powder metallurgical method of consolidating iron-based alloy powder, particularly white cast iron, to form a body of high density in which the powder is thermally cycled above and below the alpha-gamma transformation temperature of below 800.degree. C., and a stress of between 1.7 MPa and 34.5 MPa is simultaneously applied to the powder to form a high density consolidated body.

Method for consolidation of iron-based alloy powder by cyclic phase

An ultrahigh carbon steel consisting of a structure formed by divorced eutectoid transformation with or without accompanying deformation such that substantially no pearlite is formed, having a fine grained iron matrix stabilized by cementite in spheroidized form. A method for processing the steel including heat treatment and mechanical working to form spheroidized proeutectoid carbide particles then reheating the steel for a time such that the carbon is not uniformly distributed in the austentite so that upon cooling, with or without accompanying deformation, a divorced eutectoid transformation occurs leading to a structure of spheroidized cementite in a fine ferrite grain matrix.

Divorced eutectoid transformation process and product of ultrahigh

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Menlo Park, CA, United States of America

Jeffrey Wadsworth