High strength alloys for high temperature service in liquid-salt cooled energy systems
First Claim
1. A cobalt-free Υ
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-strengthened alloy consisting essentially of, expressed in weight percent of the total composition;
Cr 6.3 to 7.2Al 0.5 to 2Fe 0 to 5Mn 0.7 to 0.8Mo 9 to 12.5Ta 0 to 6Ti 0.99 to 3.5Nb 0.01 to 0.25W 0.2 to 0.6C 0.02 to 0.04B 0 to 0.0005N 0.0001 to 0.002Ni balance said alloy having a Υ
′
microstructural component in an amount of calculated weight percent of at least 3 and no more than 17.6; and
said alloy being characterized by, at 850°
C., a yield strength of at least 60 Ksi, a tensile strength of at least 70 Ksi, and a creep rupture life at 12 Ksi of at least 700 hours, and a corrosion rate, expressed in weight loss [g/(cm2sec)]10−
11 during a 1000 hour immersion in liquid FLiNaK at 850°
C., in the range of 5.5 to 17, and further characterized by a corrosion susceptibility index of no less than about 0.14 and no more than about 0.2.
2 Assignments
0 Petitions
Accused Products
Abstract
An essentially cobalt-free alloy consists essentially of, in terms of weight percent: 6.3 to 7.2 Cr, 0.5 to 2 Al, 0 to 5 Fe, 0.7 to 0.8 Mn, 9 to 12.5 Mo, 0 to 6 Ta, 0.75 to 3.5 Ti, 0.01 to 0.25 Nb, 0.2 to 0.6 W, 0.02 to 0.04 C, 0 to 0.001 B, 0.0001 to 0.002 N, balance Ni. The alloy is characterized by a γ′ microstructural component in the range of 3 to 17.6 weight percent of the total composition. The alloy is further characterized by, at 850° C., a yield strength of at least 60 Ksi, a tensile strength of at least 70 Ksi, a creep rupture life at 12 Ksi of at least 700 hours, and a corrosion rate, expressed in weight loss [g/(cm2sec)]10−11 during a 1000 hour immersion in liquid FLiNaK at 850° C., in the range of 5.5 to 17.
75 Citations
9 Claims
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1. A cobalt-free Υ
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-strengthened alloy consisting essentially of, expressed in weight percent of the total composition;Cr 6.3 to 7.2 Al 0.5 to 2 Fe 0 to 5 Mn 0.7 to 0.8 Mo 9 to 12.5 Ta 0 to 6 Ti 0.99 to 3.5 Nb 0.01 to 0.25 W 0.2 to 0.6 C 0.02 to 0.04 B 0 to 0.0005 N 0.0001 to 0.002 Ni balance said alloy having a Υ
′
microstructural component in an amount of calculated weight percent of at least 3 and no more than 17.6; and
said alloy being characterized by, at 850°
C., a yield strength of at least 60 Ksi, a tensile strength of at least 70 Ksi, and a creep rupture life at 12 Ksi of at least 700 hours, and a corrosion rate, expressed in weight loss [g/(cm2sec)]10−
11 during a 1000 hour immersion in liquid FLiNaK at 850°
C., in the range of 5.5 to 17, and further characterized by a corrosion susceptibility index of no less than about 0.14 and no more than about 0.2.
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2. An alloy in accordance with claim 1 wherein the range of Al is 0.75 to 2weight percent.
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3. An alloy in accordance with claim 1 wherein the range of Fe is 0 to 0.05weight percent.
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4. An alloy in accordance with claim 1 wherein said Υ
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microstructural component in an amount of a calculated weight percent of at least 3 and no more than 11.8.
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5. An alloy in accordance with claim 4 wherein said Υ
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microstructural component in an amount of a calculated weight percent of at least 3 and no more than 9.4.
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6. An alloy in accordance with claim 1 wherein said yield strength is at least 65 Ksi.
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7. An alloy in accordance with claim 1 wherein said tensile strength is at least 75 Ksi.
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8. An alloy in accordance with claim 1 wherein said creep rupture life is at least 750hours.
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9. An alloy in accordance with claim 1 wherein said corrosion rate is no more than 8.4.
Specification