Abstract:
A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15 % Cr, 13.6 % Co, 4.1 % Mo, 4.6 % Ti, 2.2 % Al, 0.01 % C, 0.007 % B, 0.07 % Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.
Abstract:
A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15 % Cr, 13.6 % Co, 4.1 % Mo, 4.6 % Ti, 2.2 % Al, .01 % C, 0.007 % B, 0.07 % Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least .5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.
Abstract:
High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.
Abstract:
A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15 % Cr, 13.6 % Co, 4.1 % Mo, 4.6 % Ti, 2.2 % Al, 0.01 % C, 0.007 % B, 0.07 % Zr, balance Ni. This material is forged at a temperature above the gama prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.
Abstract:
High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.
Abstract:
On décrit un procédé pour produire un article en superalliage forgé à grain fin présentant une résistance à la déformation élevée à des températures intermédiaires. Une composition de départ préférée comprend, en poids, 15 % Cr, 13,6 % Co, 4,1 % Mo, 4,6 % Ti, 2,2 % Al, 0,01 % C, 0,007 % B, 0,07 % Zr, solde Ni. On forge cette matière à une température supérieure à la courbe limite de solubilité gamma de base et à un taux de déformation réelle d'au moins 0,5. Dans un autre mode de réalisation, on forge la matière à une température inférieure à la température de la courbe limite de solubilité gamma de base avec des recuits intermédiaires de super courbe limite de solubilité. On effectue ensuite le formage de la matière survieillie à une température inférieure à la courbe limite de solubilité gamma de base. On traite alors à chaud la matière à grain fin obtenue ou l'on peut aussi la forger de manière isothermique avant de la traiter à chaud pour produire des formes complexes.
Abstract:
High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.
Abstract:
A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15 % Cr, 13.6 % Co, 4.1 % Mo, 4.6 % Ti, 2.2 % Al, 0.01 % C, 0.007 % B, 0.07 % Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.