Patents by Inventor Raghavan Ayer

Raghavan Ayer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100021761
    Abstract: Provided are strain hardened high strength nickel based alloy welds that yield improved properties and performance in joining high strength metals. The advantageous weldments include two or more segments of ferrous or non-ferrous components, and fusion welds, friction stir welds, electron beam welds, laser beam welds, or a combination thereof bonding adjacent segments of the components together, wherein the welds comprise a strain hardened nickel based alloy weld metal composition including greater than or equal to 10 wt % Mo based on the total weight of the nickel based alloy weld metal composition. Also provided are methods for forming the welds from the nickel based alloy weld compositions. The strain hardened high strength nickel based alloy welds are useful in the oil, gas and petrochemical industry in applications for natural gas transportation and storage, oil and gas well completion and production, and oil and gas refinery and chemical plants.
    Type: Application
    Filed: December 16, 2008
    Publication date: January 28, 2010
    Inventors: Raghavan Ayer, Neeraj Srinivas Thirumalai, Hyun-Woo Jin, Daniel B. Lillig, Douglas Paul Fairchild, Steven Jeffrey Ford
  • Publication number: 20090301613
    Abstract: A steel composition and method from making a dual phase steel therefrom. The dual phase steel may have carbon of about 0.05% by weight to about 0.12 wt %; niobium of about 0.005 wt % to about 0.03 wt %; titanium of about 0.005 wt % to about 0.02 wt %; nitrogen of about 0.001 wt % to about 0.01 wt %; silicon of about 0.01 wt % to about 0.5 wt %; manganese of about 0.5 wt % to about 2.0 wt %; and a total of molybdenum, chromium, vanadium and copper less than about 0.15 wt %. The steel may have a first phase consisting of ferrite and a second phase having one or more of carbide, pearlite, martensite, lower bainite, granular bainite, upper bainite, and degenerate upper bainite. A solute carbon content in the first phase may be about 0.01 wt % or less.
    Type: Application
    Filed: April 6, 2009
    Publication date: December 10, 2009
    Inventors: Jayoung Koo, Swarupa Soma Bangaru, Hyun-Woo Jin, Adnan Ozekcin, Raghavan Ayer, Douglas P. Fairchild, Danny L. Beeson, Douglas S. Hoyt, James B. LeBleu, JR., Shigeru Endo, Mitsuhiro Okatsu, Shinichi Kakihara, Moriyasu Nagae
  • Publication number: 20090155623
    Abstract: Provided are precipitation hardened high strength nickel based alloy welds that yield improved properties and performance in joining high strength metals. The advantageous weldments include two or more segments of ferrous or non-ferrous components, and fusion welds, friction stir welds, electron beam welds, laser beam welds, or a combination thereof bonding adjacent segments of the components together, wherein the welds comprise a precipitation hardened nickel based alloy weld metal composition including greater than or equal to 1.4 wt % of combined aluminum and titanium based on the total weight of the nickel based alloy weld metal composition. Also provided are methods for forming the welds from the nickel based alloy weld compositions, wherein the precipitation hardening occurs in the as-welded condition. The nickel based welds do not require a separate heat treatment step after welding to produce advantageous strength properties.
    Type: Application
    Filed: December 16, 2008
    Publication date: June 18, 2009
    Inventors: Raghavan Ayer, Neeraj Srinivas Thirumalai, Hyun-Woo Jin, Daniel B. Lillig, Douglas Paul Fairchild, Steven Jeffrey Ford
  • Publication number: 20090075118
    Abstract: Provided are metal structures and methods of forming such structures for use in oil, gas and/or petrochemical applications that are joined with non-ferrous weld metal compositions or a high alloy weld metal compositions. The welded metal structures include two or more segments of ferrous or non-ferrous components, and fusion welds, friction stir welds or a combination thereof bonding adjacent segments of the components together, wherein the welds comprise a non-ferrous weld metal composition or a high alloy weld metal composition that is substantially different from the metal composition of the two or more components. The resultant welded structures exhibit improvements in fatigue resistance, toughness, strain capacity, strength, stress corrosion cracking resistance, and hydrogen embrittlement resistance compared to traditional iron-based weld compositions.
    Type: Application
    Filed: September 18, 2007
    Publication date: March 19, 2009
    Inventors: Raghavan Ayer, Neeraj S. Thirumalai, Daniel B. Lillig, Steven J. Ford, Douglas P. Fairchild
  • Patent number: 7402277
    Abstract: The present invention relates to a method of forming metallic foams using cold spray processing. The method allows for the formation of metallic foams on existing substrates as a layer. The method includes the steps of providing a substrate for coating of a metallic foam; cold spraying a mixture of metal particles and a foaming agent onto the substrate to form a substrate coated with an unexpanded metallic layer; foam heat treating the substrate coated with an unexpanded metallic layer at a temperature above the decomposition temperature of the foaming agent for a time sufficient to form a heated substrate coated with an expanded metal foam layer; and cooling the heated substrate coated with an expanded metal foam layer to about ambient temperature to form a cooled substrate coated with an expanded metal foam layer. The method of forming metallic foams on substrates finds application in the oil, gas, and chemical industry by being an integral part of casings, pipelines, transfer lines, and other flow lines.
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: July 22, 2008
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Raghavan Ayer, Norman Pokutylowicz
  • Publication number: 20080032152
    Abstract: The use of laser shock processing in oil & gas and/or petrochemical applications is provided by the present invention. The use includes subjecting friction stir weldments, fusion weldments, and other critical regions of ferrous and non-ferrous alloy components used in oil & gas and petrochemical applications to laser shock processing to create residual compressive stresses near the surface of the treated area. The residual compressive forces in the ferrous or non-ferrous components improve properties including, inter alia, is surface strength, fatigue life, surface hardness, stress corrosion resistance, fatigue resistance, and environmental cracking resistance. Laser shock processing finds particular application in high strength pipelines, steel catenary risers, top tension risers, threaded components, liquefied natural gas containers, pressurized liquefied natural gas containers, deep water oil drill strings, riser/casing joints, and well-head equipment.
    Type: Application
    Filed: August 4, 2006
    Publication date: February 7, 2008
    Inventors: Glen A. Vaughn, Narasimha-Rao Venkata Bangaru, Jayoung Koo, Raghavan Ayer, Danny L. Beeson, Neeraj S. Thirumalai, David A. Baker, David A. Norman
  • Publication number: 20080032153
    Abstract: The use of friction stir and laser shock processing in oil & gas and/or petrochemical applications is provided by the present invention. The use includes subjecting friction stir weldments, fusion weldments, and other critical regions of ferrous and non-ferrous alloy components used in oil & gas and petrochemical applications to laser shock processing to create residual compressive stresses near the surface of the treated area. The residual compressive forces in the ferrous or non-ferrous components improve properties including, inter alia, surface strength, fatigue life, surface hardness, stress corrosion resistance, fatigue resistance, and environmental cracking resistance. Friction stir and laser shock processing find particular application in high strength pipelines, steel catenary risers, top tension risers, threaded components, liquefied natural gas containers, pressurized liquefied natural gas containers, deep water oil drill strings, riser/casing joints, and well-head equipment.
    Type: Application
    Filed: December 21, 2006
    Publication date: February 7, 2008
    Inventors: Glen A. Vaughn, Narasimha-Rao Venkata Bangaru, Jayoung Koo, Raghavan Ayer, Danny L. Beeson, Neeraj S. Thirumalai, David A. Baker, David A. Norman, Steven J. Ford, Douglas P. Fairchild
  • Publication number: 20070183919
    Abstract: The present invention relates to a method of forming metallic foams using cold spray processing. The method allows for the formation of metallic foams on existing substrates as a layer. The method includes the steps of providing a substrate for coating of a metallic foam; cold spraying a mixture of metal particles and a foaming agent onto the substrate to form a substrate coated with an unexpanded metallic layer; foam heat treating the substrate coated with an unexpanded metallic layer at a temperature above the decomposition temperature of the foaming agent for a time sufficient to form a heated substrate coated with an expanded metal foam layer; and cooling the heated substrate coated with an expanded metal foam layer to about ambient temperature to form a cooled substrate coated with an expanded metal foam layer. The method of forming metallic foams on substrates finds application in the oil, gas, and chemical industry by being an integral part of casings, pipelines, transfer lines, and other flow lines.
    Type: Application
    Filed: February 7, 2006
    Publication date: August 9, 2007
    Inventors: Raghavan Ayer, Norman Pokutylowicz
  • Publication number: 20070181647
    Abstract: A method for welding and repairing cracks in metal parts is provided by subjecting the metal parts to be welded to friction stir welding and the cracks to be repaired to friction stir processing under conditions sufficient to provide a weld joint or crack repair having a preselected property or set of properties based upon the intended use of the weldment. The FSW and FSP methods are advantageous in joining and repairing metal structures and components in applications for natural gas transportation and storage, oil and gas well completion and production, and oil and gas refinery and chemical plants.
    Type: Application
    Filed: December 21, 2006
    Publication date: August 9, 2007
    Inventors: Steven Ford, Neeraj Thirumalai, James Rigby, Mark Biegler, Narasimha-Rao Venkata Bangaru, Jayoung Koo, Glen Vaughn, Raghavan Ayer, Douglas Fairchild
  • Publication number: 20070175967
    Abstract: A method for welding and repairing cracks in metal parts is provided by subjecting the metal parts to be welded to friction stir welding and the cracks to be repaired to friction stir processing under conditions sufficient to provide a weld joint or crack repair having a preselected property or set of properties based upon the intended use of the weldment.
    Type: Application
    Filed: December 15, 2006
    Publication date: August 2, 2007
    Inventors: Narasimha-Rao Venkata Bangaru, Jayoung Koo, Glen A. Vaughn, Raghavan Ayer, Douglas P. Fairchild
  • Patent number: 6254698
    Abstract: An ultra-high strength, weldable, low alloy steel with excellent cryogenic temperature toughness in the base plate and in the heat affected zone (HAZ) when welded, having a tensile strength greater than about 830 MPa (120 ksi) and a microstructure comprising (i) predominantly fine-grained lower bainite, fine-grained lath martensite, fine granular bainite (FGB), or mixtures thereof, and (ii) up to about 10 vol % retained austenite, is prepared by heating a steel slab comprising iron and specified weight percentages of some or all of the additives carbon, manganese, nickel, nitrogen, copper, chromium, molybdenum, silicon, niobium, vanadium, titanium, aluminum, and boron; reducing the slab to form plate in one or more passes in a temperature range in which austenite recrystallizes; finish rolling the plate in one or more passes in a temperature range below the austenite recrystallization temperature and above the Ar3 transformation temperature; quenching the finish rolled plate to a suitable Quench Stop Temperat
    Type: Grant
    Filed: December 19, 1998
    Date of Patent: July 3, 2001
    Assignee: ExxonMobile Upstream Research Company
    Inventors: Jayoung Koo, Narasimha-Rao V. Bangaru, Glen A. Vaughn, Raghavan Ayer
  • Patent number: 6159312
    Abstract: An ultra-high strength, weldable, low alloy, triple phase steel with excellent cryogenic temperature toughness in the base plate and in the heat affected zone (HAZ) when welded, having a tensile strength greater than about 830 MPa (120 ksi) and a microstructure comprising a ferrite phase, a second phase of predominantly lath martensite and lower bainite, and a retained austenite phase, is prepared by heating a steel slab comprising iron and specified weight percentages of some or all of the additives carbon, manganese, nickel, nitrogen, copper, chromium, molybdenum, silicon, niobium, vanadium, titanium, aluminum, and boron; reducing the slab to form plate in one or more passes in a temperature range in which austenite recrystallizes; further reducing the plate in one or more passes in a temperature range below the austenite recrystallization temperature and above the Ar.sub.3 transformation temperature; finish rolling the plate between the Ar.sub.3 transformation temperature and the Ar.sub.
    Type: Grant
    Filed: December 19, 1998
    Date of Patent: December 12, 2000
    Assignee: ExxonMobil Upstream Research Company
    Inventors: Jayoung Koo, Narasimha-Rao V. Bangaru, Raghavan Ayer, Glen A. Vaughn
  • Patent number: 4818481
    Abstract: Disclosed is a method for extruding fine grain aluminum mechanically alloyed powder material such that the resulting extruded product is substantially free of texture, which method comprises extruding a billet of the powder material having a mean grain size less than about 5 microns through a die having an internal contour which conforms substantially to the formula: ##EQU1## where R is the radius of the die contour at any given point x along the major axis of the die orifice from its entry plane, R.sub.o is the radius of the billet, and K is an arbitrary constant.
    Type: Grant
    Filed: March 9, 1987
    Date of Patent: April 4, 1989
    Assignee: Exxon Research and Engineering Company
    Inventors: Michael J. Luton, Raghavan Ayer, Ruzica Petkovic-Luton, Joseph Vallone, Stephen Matras
  • Patent number: 4427447
    Abstract: Disclosed are metal powders mixtures which can be mechanically alloyed into oxide dispersion strengthened high temperature alloys. The powder mixtures contain from 0 to 30 wt. % chromium, about 0 to 3 wt. % titanium, about 0.3 wt. % to 10 wt. % aluminum, and from about 0.3 wt. % to 10 wt. % particles of one or more alumina-yttria mixed- oxides selected from the group consisting of Al.sub.2 O.sub.3.2Y.sub.2 O.sub.3, Al.sub.2 O.sub.3.Y.sub.2 O.sub.3, and 5Al.sub.2 O.sub.3.3Y.sub.2 O.sub.3.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: January 24, 1984
    Assignee: Exxon Research and Engineering Co.
    Inventors: Trikur A. Ramanarayanan, Ruzica Petkovic-Luton, Raghavan Ayer
  • Patent number: 4402746
    Abstract: Disclosed are oxide dispersion strengthened high temperature alloy compositions which contain as the dispersoid one or more alumina-yttria mixed-oxides selected from the group consisting of Al.sub.2 O.sub.3.2Y.sub.2 O.sub.3, Al.sub.2 O.sub.3.Y.sub.2 O.sub.3, and 5Al.sub.2 O.sub.3.3Y.sub.2 O.sub.3.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: September 6, 1983
    Assignee: Exxon Research and Engineering Co.
    Inventors: Trikur A. Ramanarayanan, Ruzica Petkovic-Luton, Raghavan Ayer