Ati Properties, Inc.

Allegheny Ludlum Corporation

Ronald E Bailey

Glenn J Swiatek

Thomas R Parayil

Njall Stefansson

Tong C Lee

Timothy M Hackett

William W Timmons

David C Berry

Anthony J Polito

Bradley Hasek

Robert H Bell

Andrew Nichols

Thomas Parayil

A dual hardness steel article comprises a first air hardenable steel alloy having a first hardness metallurgically bonded to a second air hardenable steel alloy having a second hardness. A method of manufacturing a dual hard steel article comprises providing a first air hardenable steel alloy part comprising a first mating surface and having a first part hardness, and providing a second air hardenable steel alloy part comprising a second mating surface and having a second part hardness. The first air hardenable steel alloy part is metallurgically secured to the second air hardenable steel alloy part to form a metallurgically secured assembly, and the metallurgically secured assembly is hot rolled to provide a metallurgical bond between the first mating surface and the second mating surface.

Dual hardness steel article

A process for reducing flatness deviations in an alloy article is disclosed. An alloy article may be heated to a first temperature at least as great as a martensitic transformation start temperature of the alloy. A mechanical force may be applied to the alloy article at the first temperature. The mechanical force may tend to inhibit flatness deviations of a surface of the alloy article. The alloy article may be cooled to a second temperature no greater than a martensitic transformation finish temperature of the alloy. The mechanical force may be maintained on the alloy article during at least a portion of the cooling of the alloy article from the first temperature to the second temperature.

Processes for reducing flatness deviations in alloy articles

Method of making a dual hardness steel article

One aspect of the present disclosure is directed to low-alloy steels exhibiting high hardness and an advantageous level of multi-hit ballistic resistance with minimal crack propagation imparting a level of ballistic performance suitable for military armor applications. Certain embodiments of the steels according to the present disclosure have hardness in excess of 550 HBN and demonstrate a high level of ballistic penetration resistance relative to conventional military specifications.

Methods for making high hardness, high toughness iron-base alloys

An air hardenable steel alloy is disclosed comprising, in percent by weight: 0.18 to 0.26 carbon; 3.50 to 4.00 nickel; 1.60 to 2.00 chromium; 0 to 0.50 molybdenum; 0.80 to 1.20 manganese; 0.25 to 0.45 silicon; 0 to less than 0.005 titanium; 0 to less than 0.020 phosphorus; 0 up to 0.005 boron; 0 up to 0.003 sulfur; iron; and impurities. The air hardenable steel alloy has a Brinell hardness in a range of 352 HBW to 460 HBW. The air hardenable steel alloy combines high strength, medium hardness and toughness, as compared with certain known air hardenable steel alloys, and finds application in, for example, any of a steel armor, a blast-protective hull, a blast-protective V-shaped hull, a blast-protective vehicle underbelly, and a blast-protective enclosure.

Air hardenable shock-resistant steel alloys, methods of making the alloys, and articles including the alloys

An aspect of the present disclosure is directed to low-alloy steels exhibiting high hardness and an advantageous level of multi-hit ballistic resistance with low or no crack propagation imparting a level of ballistic performance suitable for military armor applications. Various embodiments of the steels according to the present disclosure have hardness in excess of 550 BHN and demonstrate a high level of ballistic penetration resistance relative to conventional military specifications.

High hardness, high toughness iron-base alloys and methods for making same

Maraging steel compositions, methods of forming the same, and articles formed therefrom comprising, by weight, 15.0 to 20.0% Ni, 2.0 to 6.0% Mo, 3.0 to 8.0% Ti, up to 0.5% Al, the balance Fe and residual impurities. The composition may be a first layer of a composite plate, and may have a second layer deposited on the first layer, the second layer having a composition comprising, by weight, 15.0 to 20.0% Ni, 2.0 to 6.0% Mo, 1.0 to 3.0 Ti, up to 0.5% Al, the balance Fe and residual impurities. The first layer may have a hardness value ranging from 58 to 64 RC, and the second layer may have a hardness value ranging from 48 to 54 RC. The first layer may be formed employing powdered metallurgical techniques. Articles formed from the compositions include armored plate.

Steel compositions, methods of forming the same, and articles formed therefrom

A method of producing steel armor plate having improved resistance to penetration by projectiles. The armor plate provides for intended inclusions, generally elliptically shaped, in the steel oriented substantially parallel to the plate surface. Those inclusions result from at least one element of the steel composition selected from the group of sulfur and oxygen. The steel armor plate may be useful with an increased inclusion level on the front approximately one-half portion of the dual hardness composite steel armor plate so as to spread out the force of the impact over a wider area.

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Pittsburgh, PA, United States of America

Ronald E Bailey