EP0091279A1
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EP
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Ni-base alloy member and method of producing the same
Assignee: Hitachi Ltd
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Filing: 1983-03-30
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Granted: —
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Expires: 2003-03-30
Abstract
Abstract A nickel-base alloy with high stress corrosion cracking resistance and suitable for use as material for springs and bolts used in nuclear reactors consists essentially of, by weight, up to 0,15%C, up to 1%Si, up to 1,5%Mn, 14 to 25%Cr, up to 30%Fe, 0,2 to 2%Al, 0,5 to 3%Ti, 0,7 to 4,5%Nb and the balance substantially Ni, the high stress corrosion cracking resistance of this alloy in high-purity water at high temperatures and pressures (typically 288°C, 86kg(cm 2 ) is obtained by 1) cold plastic working at a ratio of at least 40% between the solution heat treatment and the direct aging treatment or 2) cold plastic working at a ratio of beyond 25% between the solution heat treatment and a two-stepped aging treatment.
Inventors
- 👤 Yoshinao Urayama
- 👤 Shigeo Hattori
- 👤 Isao Masaoka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 09:36
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/03; C22C19/05; C22C19/058; C22F; C22F1/00; C22F1/10
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
113 words
An Ni-base alloy memamber superior in stress corrosion cracking resistance made of an alloy consisting essentially of, by weight, not greater than 0.15% of C, not greater than 1% of Si, not greater than 1.5% of Mn, 14 to 25% of Cr, not greater than 30% of Fe, 0.2.to 2% of Al, 0.5 to 3% of Ti, 0.7 to 4.5% of Nb and the balance substantially Ni, characterized in that said alloy exhibits stress corrosion cracking depth of not greater than 200um when subjected to pure water of 288°C under a pressure of 86 Kg/cm 2 and having a dissolved oxygen content of 8 ppm, for 500 hours at a strain of 1%.
Claim 2
Dependent Claim
113 words
An Ni-base alloy memamber superior in stress corrosion cracking resistance made of an alloy consisting essentially of, by weight, not greater than 0.15% of C, not greater than 1% of Si, not greater than 1.5% of Mn, 14 to 25% of Cr, not greater than 30% of Fe, 0.2.to 2% of Al, 0.5 to 3% of Ti, 0.7 to 4.5% of Nb and the balance substantially Ni, characterized in that said alloy exhibits stress corrosion cracking depth of not greater than 200um when subjected to pure water of 288°C under a pressure of 86 Kg/cm 2 and having a dissolved oxygen content of 8 ppm, for 500 hours at a strain of 1%.
Claim 3
Dependent Claim
30 words
An Ni-base alloy member according to claim 1, wherein said alloy has a structure containing discontinuous granular precipitate of Cr carbide along the grain boundary or a primary recrystallization structure.
Claim 4
Dependent Claim
133 words
An Ni-base alloy member superior in stress corrosion cracking resistance made of an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 to 1% of Mn, 14 to 20% of Cr, not greater than 10% of Fe, 0.4 to 1.0% of Al, 2 to 3 % of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni, characterized in that said alloy has a structure containing discontinuous granular precipitate of Cr carbide along the grain boundary or an apparent primary recrystallization structure and exhibits stess corrosion cracking length of not greater than 200um when subjected to pure water of 288°C under a pressure of 86 Kg/cm 2 and having a dissolved oxygen content of 8 ppm, for 500 hours at a strain of 1%.
Claim 5
Dependent Claim
133 words
An Ni-base alloy member superior in stress corrosion cracking resistance made of an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 to 1% of Mn, 14 to 20% of Cr, not greater than 10% of Fe, 0.4 to 1.0% of Al, 2 to 3 % of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni, characterized in that said alloy has a structure containing discontinuous granular precipitate of Cr carbide along the grain boundary or an apparent primary recrystallization structure and exhibits stess corrosion cracking length of not greater than 200um when subjected to pure water of 288°C under a pressure of 86 Kg/cm 2 and having a dissolved oxygen content of 8 ppm, for 500 hours at a strain of 1%.
Claim 6
Dependent Claim
35 words
An Ni-base alloy member according to claim 3, wherein said member is used as the material for a spring or a bolt subjected to pure water of high temperatue and pressure in a nuclear reactor.
Claim 7
Dependent Claim
131 words
An Ni-base alloy member superior in stress corrosion cracking resistance made of an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 to 1% of Mn, 14 to 17% of Cr, 5 to 9% of Fe, 0,4 to 1.0% of Al, 2 to 3% of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni, characterized in that said alloy has a structure containing discontinuous granular precipitate of Cr carbide along the grain boundary or an apparent primary recrystallization structure and exhibits stress corrosion cracking depth of not greater than 200pm when subjected to pure water of 288°C under a pressure of 86 Kg/cm 2 and having dissolved oxygen content of 8 ppm, for 500 hours at a strain of 1%. «
Claim 8
Dependent Claim
131 words
An Ni-base alloy member superior in stress corrosion cracking resistance made of an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 to 1% of Mn, 14 to 17% of Cr, 5 to 9% of Fe, 0,4 to 1.0% of Al, 2 to 3% of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni, characterized in that said alloy has a structure containing discontinuous granular precipitate of Cr carbide along the grain boundary or an apparent primary recrystallization structure and exhibits stress corrosion cracking depth of not greater than 200pm when subjected to pure water of 288°C under a pressure of 86 Kg/cm 2 and having dissolved oxygen content of 8 ppm, for 500 hours at a strain of 1%. «
Claim 9
Dependent Claim
35 words
An Ni-base alloy member according to claim 5, wherein said member is used as the material for a spring or a bolt subjected to pure water of high temperature and pressure in a nuclear reactor.
Claim 10
Independent Claim
116 words
A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, not greater than 0.15% of C, not greater than 1% of Si, not greater than 1.5% of Mn, 14 to 25% of Cr, not greater than 30% of Fe, 0.2 to 2% of Al, 0.5 to 3% of Ti, 0.7 to 4.5% of•Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 40%; and subjecting said alloy to an aging treatment at a temperature of between 650 and 750°C.
Claim 11
Independent Claim
116 words
A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, not greater than 0.15% of C, not greater than 1% of Si, not greater than 1.5% of Mn, 14 to 25% of Cr, not greater than 30% of Fe, 0.2 to 2% of Al, 0.5 to 3% of Ti, 0.7 to 4.5% of•Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 40%; and subjecting said alloy to an aging treatment at a temperature of between 650 and 750°C.
Claim 12
Dependent Claim
24 words
A method according to claim 7, wherein said cold plastic working is effected at a reduction of cross-sectional area of between 50 and 70%.
Claim 13
Independent Claim
114 words
A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 to 1% of Mn, 14 to 20% of Cr, not greater than 10% of Fe, 0.4 to 1% of Al, 2 to 3% of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 40%; and subjecting said alloy to an aging treatment at a temperature of between 650 and 750°C.
Claim 14
Independent Claim
114 words
A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 to 1% of Mn, 14 to 20% of Cr, not greater than 10% of Fe, 0.4 to 1% of Al, 2 to 3% of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 40%; and subjecting said alloy to an aging treatment at a temperature of between 650 and 750°C.
Claim 15
Dependent Claim
24 words
A method according to claim 9, wherein said cold plastic working is effected at a reduction of cross-sectional area of between 50 and 70%.
Claim 16
Dependent Claim
133 words
ll. A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, not greater than 0.15% of C, not greater than 1% of Si, not greater than 1.5% of Mn, 14 to 25% of Cr, not greater than 30% of Fe, 0.2 to 2% of Al, 0.5 to 3% of Ti, 0.7 to 4.5% of Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 25%; subjecting said alloy to an aging treatment at a temperature of between 800 and 950°C; and subjecting said alloy to another aging treatment at a temperature of between 600 and 750°C.
Claim 17
Dependent Claim
133 words
ll. A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, not greater than 0.15% of C, not greater than 1% of Si, not greater than 1.5% of Mn, 14 to 25% of Cr, not greater than 30% of Fe, 0.2 to 2% of Al, 0.5 to 3% of Ti, 0.7 to 4.5% of Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 25%; subjecting said alloy to an aging treatment at a temperature of between 800 and 950°C; and subjecting said alloy to another aging treatment at a temperature of between 600 and 750°C.
Claim 18
Dependent Claim
24 words
A method according to claim 11, wherein said cold plastic working is effected at a reduction of cross-sectional area of between 40 and 70%.
Claim 19
Independent Claim
128 words
A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 toll% of Mn, 14 to 20% of Cr, not greater than 10% of Fe, 0.4 to 1% of Al, 2 to 3% of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 25%; sujecting said alloy to an aging treatment at a temperature of between 800 and 950°C; and subjecting said alloy to another aging treatment at a temperature of between 600 and 750°C.
Claim 20
Independent Claim
128 words
A method of producing an Ni-base alloy member superior in stress corrosion cracking resistance comprising the steps of: preparing an alloy consisting essentially of, by weight, 0.02 to 0.08% of C, 0.02 to 0.5% of Si, 0.1 toll% of Mn, 14 to 20% of Cr, not greater than 10% of Fe, 0.4 to 1% of Al, 2 to 3% of Ti, 0.7 to 1.5% of Nb and the balance substantially Ni; subjecting said alloy to a solution heat treatment; effecting a cold plastic working on said alloy at a reduction of cross-sectional area not smaller than 25%; sujecting said alloy to an aging treatment at a temperature of between 800 and 950°C; and subjecting said alloy to another aging treatment at a temperature of between 600 and 750°C.
Claim 21
Dependent Claim
24 words
A method according to claim 13, wherein said cold plastic working is effected at a reduction of cross-sectional area of between 40 and 70%.
References Cited (Backward Citations)
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