Abstract: A .gamma.' precipitation strengthened nickel-base superalloy provided in powder metal or cast and wrought form and alloyed to minimize nucleation tendencies and control grain growth. The superalloy includes a fine dispersion of a second phase in sufficient amounts to prevent critical grain growth in the superalloy when the superalloy is subjected to temperatures above its .gamma.' solvus temperature. The superalloy preferably contains at least about 0.030 weight percent carbon or about 27 to about 2000 ppm yttrium in order to produce a volume fraction of the second phase which is sufficient to cover a minimum of about 10 percent of the grain boundary area.

Abstract: A method is provided for obtaining uniform grain growth within .gamma.' precipitation strengthened nickel-base superalloys provided in powder metal or cast and wrought form. The method includes alloying the nickel-base superalloy to contain a minimum calculated amount of carbon which, when finely dispersed within the alloy using suitable processing methods, yields a sufficient amount of carbide phase which restricts the grain boundary motion of the alloy during supersolvus heat treatment. When appropriately processed, the grains are not permitted to grow randomly during supersolvus heat treatment, making possible a microstructure whose grain size is uniform, having a grain size range of about 2 to about 3 ASTM units and being substantially free of random grain growth in excess of about 2 ASTM units coarser than the desired grain size range.

Abstract: A method is provided for obtaining uniform grain growth within .gamma.' precipitation strengthened nickel-base superalloys. The method includes forming a billet having a very fine grain size in order to achieve optimum superplasticity of the superalloy during forging. The article is then heated to a pre-working hold temperature in a manner which prevents coarsening of the microstructure and a loss of superplasticity. The article is then worked, such as by forging, at a temperature below the .gamma.' solvus temperature of the alloy, so as to maintain local strain rates within the article below a critical strain rate for random grain growth, and so as to maintain the strain rate gradient throughout the article below a critical upper limit. After working, the article is subjected to annealing at a temperature which is less than the .gamma.' solvus temperature of the alloy, and for a duration which is sufficient to remove accumulated metallurgical strain in the article.

Abstract: A duplex strengthened structural steel that is particularly suitable for demanding applications which require both high yield strength and fatigue properties is provided. The preferred steel alloys of this invention are characterized by both the presence of intermetallic strengthening precipitates like maraging steels, as well as alloy carbide strengtheners as is common with secondary hardening steels. Titanium is substantially absent from the preferred steel alloys of this invention. Thus the formation of nonmetallic inclusions, such as titanium carbonitrides, are alleviated which correspondingly enhances the fatigue properties of the preferred alloys. To compensate for the lack of titanium strengthening precipitates within the alloy, additions of aluminum are provided such that the aluminum forms intermetallic strengthening precipitates with nickel.

Abstract: A structure having a metal body with a plurality of intersecting cavities and a consolidated corrosion resistant powdered metal lining and metallurgically engaging the walls of the intersecting cavities.

Abstract: The method of forming a lining in the cavities of a body by application of powdered metal consolidated and bonded thereon by a hot isostatic pressing process. A space lining the cavities in the body is provided by tubular members, one intersecting with the other or in close spaced relation thereto, powdered metal fills the space, a vacuum is drawn on the space, the body is subjected to forming conditions and then the body cavities are machined to their final shape with such machining generally removing the tubular members.

Abstract: An improved forged steel structure lined with a corrosion resistant metal in which the lining and body are forged together. The improved method includes the steps of securing a bar of corrosion resistant metal within an alloy steel tube to form a billet, forging the billet to the desired shape with sufficient corrosion resistant metal to line at least one of the cavities of the desired shape and machining the forging to produce the desired lined structure. The amount of alloy steel and corrosion resistant metal in the billet being preselected to provide the desired lining without substantially weakening the structure.

Abstract: A security device used to check a door in a partially open position to prevent unauthorized entrance into a room having a doorway normally closed by the door. The security device has an anchor assembly, including a lag bolt secured to the door frame adjacent the door knob when the door is in a closed position. The lag bolt has a body carrying a head located outwardly from the frame. A rigid ring having an inside diameter slightly greater than the diameter of the door knob is attached to the anchor assembly with a link chain. The link chain has an anchor link surrounding the body of the lag screw and a ring link extended through the ring. A spacer sleeve surrounding the body of the anchor assembly holds the anchor link adjacent the head spaced from the frame and casing of the doorway. The intermediate chain links connecting the anchor link with the ring link are surrounded with a sleeve.

Abstract: The method of forming a lining in the cavities of a body by application of powdered metal consolidated and bonded thereon by a hot isostatic pressing process. A space lining the cavities in the body is provided by tubular members, one intersecting with the other or in close spaced relation thereto, powdered metal fills the space, a vacuum is drawn on the space, the body is subjected to forming conditions and then the body cavities are machined to their final shape with such machining generally removing the tubular members.