Abstract: Methods of making cylindrical structures with cooling channels, such as, for example, combustor/transition pieces for gas turbines having a double wall with a plurality of cooling channels, both axially and, in some cases, circumferential cross-flow passages positioned between the structure's inner member and the outer member to provide cooling air thereto, are disclosed. The cooling channels are formed in the area between the inner member of the structure and the outer member thereof. The passages preferably extend both axially and circumferentially with respect to the direction of flow through the structure. The axial passages extend completely from one end to the other and the circumferential passages extend around the circumference of the structure.

Abstract: An introduction system for introducing an atmosphere into an interior of an autoclave alters an existing atmosphere. The introduction system comprises at least one source of actuating gas; an actuating mechanism, a pressure barrier that separates an interior of the autoclave from ambient exterior atmosphere; and a containment vessel that is located at least partially in the interior of the autoclave. The containment vessel comprises a plurality of walls, at least one of the walls comprising a release wall structure of the containment vessel, a vapor producing material cavity, where the walls define the vapor producing material cavity; and an opening element. The opening element is movable by the opening actuator device. The release wall structure of the containment vessel is rapidly opened by the opening element to effect a rapid release of vapor producing material in the vapor producing material cavity into the interior of the autoclave.

Abstract: A stainless steel comprises additives including at least one of rare earth elements and boron, so as to exhibit resistance to long term aging embrittlement. The stainless steel also contains balanced amounts of nickel and cobalt to minimize a ration of nickel to cobalt and optimize aging embrittlement resistance with as tempered toughness. The remainder of the stainless steel comprising, by weight percentage:______________________________________ Carbon 0.08-0.15 Silicon 0.01-0.10 Chromium 8.00-13.00 At least one of Tungsten and Molybdenum 0.50-4.00 At least one Austenite stabilizer, 0.001-6.00 such as Nickel, Cobalt, Manganese and Copper Vanadium 0.25-0.40 Phosphorus 0.010 max. Sulfur 0.004 max. Nitrogen 0.060 max. Hydrogen 2 ppm max. Oxygen 50 ppm max. Aluminum 0.001-0.025 Arsenic 0.0060 max. Antimony 0.0030 max. Tin 0.0050 max. Iron Balance.

Abstract: A double wall hot gas path part for turbines, such as an airfoil, combustor, duct or shroud, comprises an outer skin and an inner support wall that are metallurgically bonded to one another. The double wall contains integral channels for passage of cooling air adjacent to the skin. The skin may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures. Microlaminate composites typically have a lower density than that of the material used for the support wall, and a simplified internal geometry, which promote weight reductions in the parts and increases in engine operating efficiency.

Abstract: A method for mitigating crack initiation and propagation on the surface of metal components in a water-cooled nuclear reactor. A metal coating having an electrically insulating outer layer is applied on the surfaces of IGSCC-susceptible reactor components. The preferred metal coating is a zirconium alloy with a zirconia outer layer. The presence of an electrically insulating layer on the surface of the metal components shifts the corrosion potential in the negative direction without the addition of hydrogen and in the absence of a noble metal catalyst. Corrosion potentials.ltoreq.-0.5 V.sub.SHE can be achieved even at high oxidant concentrations and in the absence of hydrogen.

Abstract: Quantum splitting phosphors with host lattices activated by praseodymium +3 where covalency of the Pr.sup.+3 -ligand bond is maintained so that the center of gravity of the Pr.sup.+3 4f5d band level is located above the .sup.1 S.sub.0 level and the host lattice has a band gap of greater than about 5 eV.

Abstract: An extension is formed directly on the end of an article by dipping the end into a molten bath of an alloy, followed by withdrawal of the end at a rate sufficient to form the extension. Extensions formed have a microstructure that is continuous and compatible with that of the article. Such microstructures may include epitaxial growth of the extension onto the microstructure of the article. The method establishes a temperature gradient within the article that may be controlled by heating and/or cooling the article during the practice of the method.

Abstract: Methods for controlling the superheat of the stream of molten metal from an electroslag refining apparatus is taught. The methods include the introduction of unrefined metal into an electroslag refining process apparatus in which the unrefined metal is first melted at the upper surface of the refining slag. The molten metal is refined as it passes through the molten slag. The refined metal is collected in a cold hearth apparatus having a skull of refined metal formed on the surface of the cold hearth for protecting the cold hearth from the leaching action of the refined molten metal. A cold finger bottom pour spout or exit orifice is formed at the bottom of the cold hearth to permit dispensing of molten refined metal from the cold hearth.

Abstract: A method for forming nickel base superalloy articles of manufacture by a combination of hot die forging, isothermal forging and heat treatment below and above the solvus.

Abstract: A water exclusion device for underwater arc welding comprises a chamber having flexible gas permeable surface contact member at the lower end. A wire mesh material is the preferred gas permeable material.

Abstract: A superconductive article is made from interconnected superconductive, metallic tapes. The tapes preferably are mechanically joined and electrically interconnected by a plurality of superconductive interconnections that extend between the tapes. The interconnections are formed by overlapping the edges of two tapes and forming a plurality of superconductive welds between the tapes in the overlapping regions. Articles of this invention may be formed from superconductive tapes made from Nb.sub.3 Sn having superconductive interconnections that also include Nb.sub.3 Sn.

Abstract: An extension is formed directly on an article by casting a compatible material into a ceramic mold that is attached on an end of the article, followed by cooling of the end under controlled conditions sufficient to cause an integral extension to solidify on the article. A ceramic mold is utilized over the end of the article, with a mold cavity that generally defines the shape of the extension to be formed. The mold may be formed in situ on the mandrel, or preformed and attached to the subject article over the mandrel. Extensions formed by the method of this invention have a microstructure that is continuous and compatible with that of the article. Such microstructures may include epitaxial growth of the extension from the microstructure of the article. The method establishes a temperature gradient within the article during solidification that may be further controlled by auxiliary heating and/or cooling of the article and/or extension during the practice of the method.

Abstract: Systems and methods are disclosed for exhausting and combined exhausting and seasoning of x-ray tubes having glass envelopes for a high performance x-ray system having a rotating anode therein. The methods include providing a glass tubulation having a diameter greater than about 20 mm, then operatively connecting the glass tubulation to the x-ray tube glass envelope, providing a glass sealing cup inside the glass tubulation, the glass sealing cup having a smaller diameter than the glass tubulation, providing a vacuum to the glass tubulation, positioning a heater on the outside of the glass tubulation, heating the anode of the x-ray tube to a temperature inside the x-ray tube glass envelope of about 1500.degree. C., positioning the glass sealing cup inside the glass tubulation proximate the position of the heating means on the outside of the glass tubulation, heating the glass tubulation proximate the glass sealing cup to about 1300.degree. C.

Abstract: Improved methods of exhausting and combined exhausting and seasoning of x-ray tube envelopes for high performance x-ray system having a rotating anode therein which includes providing a glass tubulation having a diameter greater than about 20 mm then operatively connecting the glass tubulation to the x-ray tube envelope, providing a disk inside the glass tubulation, the disk having a smaller diameter than the glass tubulation, providing a vacuum to the glass tubulation; positioning heating means on the outside of the glass tubulation, heating the anode of the x-ray tube to a temperature temperatures inside the x-ray tube envelope of about 1500.degree. C., positioning the disk inside the glass tubulation proximate the position of the heating means on the outside of the glass tubulation, heating the glass tubulation proximate the disk to about 1300.degree. C.

Abstract: An analyzer is employed for detecting a cloud in an optical disc having a transparent surface layer atop a substrate and data pits therebetween. A light beam is projected at an acute incidence angle atop the surface layer to define a light spot covering a plurality of the pits. Light scattered from the pits below the spot is detected obliquely to both the incident light beam and a specular reflection thereof. The light spot is scanned over the surface layer, and variation of detected light intensities over the disc is determined for detecting a cloud. In a preferred embodiment, the scattered light is detected from two different oblique directions to increase contrast of the cloud.

Abstract: A combustor/transition piece for a gas turbine including a double walled structure having a plurality of cooling channels, both axially and, in some cases, circumferential cross-flow passages positioned between the structure's inner member and the outer member to provide cooling air thereto, are formed in the area between the inner member of the combustor and the outer member thereof. The passages preferably extend both axially and circumferentially with respect to the direction of flow through the combustor/transition piece. The axial passages extend completely from one end to the other and the circumferential passages extend around the circumference of the combustor/transition piece. The addition of a circumferential cross-flow passage connecting axial flow coolant passages in double wall turbine components can prevent combustor/transition piece part failure due to axial passage inlet blockage without affecting normal, unblocked cooling.

Abstract: Improved systems and methods are disclosed for exhausting and combined exhausting and seasoning of x-ray tubes having metal envelopes for high performance x-ray systems having a rotating anode therein. The methods and systems for sealing a metal tubulation, having a diameter greater than about 20 mm and operatively connected to the x-ray tube metal envelope, to a metal disk positioned inside the metal tubulation, the metal disk having a smaller diameter than at least one portion of the metal tubulation include providing a vacuum connection to the metal tubulation and a heater positioned on the outside of the metal tubulation; heating the anode of the x-ray tube to temperatures inside the x-ray tube metal envelope of about 1500.degree. C.

Abstract: Improved systems and methods are disclosed for exhausting and combined exhausting and seasoning of x-ray tubes having glass envelopes for high performance x-ray system having a rotating anode therein. The systems and methods include using a metal tubulation having a diameter greater than about 20 mm operatively connected to a glass tubulation having a diameter greater than about 20 mm which is in turn connected to a glass x-ray tube envelope; positioning a metal disk inside the metal tubulation, the metal disk having a smaller diameter than at least one portion of the metal tubulation, and connecting a vacuum pump to the metal portion of the tubulation; positioning heating means on the outside of the metal portion of the tubulation, heating the anode of the x-ray tube to a temperature inside the x-ray tube envelope to about 1500.degree. C.

Abstract: Si-Fe-Cr base coating alloys that significantly promote the oxidation resistance of niobium-base alloys and intermetallic materials when deposited and reaction bonded to the niobium-base material. The coating alloys are deposited and then reaction bonded to a niobium-base material to yield an oxidation-resistant coating comprising an interaction layer containing at least one oxidation-resistant Si-Fe-Nb-Cr intermetallic phase.

Abstract: Stress corrosion cracking damage to stainless steels and nickel base superalloys is repaired by underwater plasma transferred arc welding which under conditions which reduce residual tensile stresses in the weld and adjacent portions of the repaired structure.