US 2015/0307976 A1Published application

Zirconium alloys with improved corrosion/creep resistance due to final heat treatments

AssigneeWestinghouse Electric Corp.

InventorsJOHN P. FOSTER, ROBERT J. COMSTOCK, ANDREW ATWOOD, GUIRONG PAN, ANAND GARDE, MATS DAHLBACK, JONNA PARTEZANA MUNDORFF, ANDREW J. MUELLER

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

The invention relates to zirconium-based alloys and articles produced therefrom, such as tubing or strips, which have at least one of excellent corrosion resistance to water or steam and creep resistance at elevated temperatures in a nuclear reactor. The alloys include from about 0.2 to 1.5 weight percent niobium, from about 0.01 to 0.6 weight percent iron, from about 0.0 to 0.8 weight percent tin, from about 0.0 to 0.5 weight percent chromium, from about 0.0 to 0.3 weight percent copper, from about 0,0 to 0.3 weight percent vanadium, and from about 0.0 to 0.1 weight percent nickel with the balance at least 97 weight percent zirconium, including impurities. Further, the articles are formed by processes that include final heat treatment of (i) SRA or PRXA (0-33% RXA), or (ii) RXA or PRXA (80-100% RXA).

Claims22

Dependent claims

A zirconium-based alloy having one of improved corrosion resistance and improved creep resistance, for use in an elevated temperature environment of a nuclear reactor, comprising an alloying composition:

0.2 to 1.5 weight percent niobium;
0.01 to 0.6 weight percent iron;
0.0 to 0.8 weight percent tin;
0.0 to 0.5 weight percent chromium;
0.0 to 0.3 weight percent copper;
0.0 to 0.3 weight percent vanadium;
0.0 to 0.1 weight percent nickel;
and
a balance at least 97 weight percent zirconium, including impurities, the zirconium-based alloy formed by a process, comprising:
(a) melting the alloying composition to produce a melted alloy material;
(b) forging the melted alloy material to produce a forged alloy material;
(c) quenching the forged alloy material to produce a quenched alloy material;
(d) extruding the quenched alloy material to produce a tube-shell alloy material;
(e) pilgering the tube-shell alloy material to produce a reduced tube-shell alloy material;
(f) annealing the reduced tube-shell alloy material to produce an annealed alloy material;
(g) repeating steps (e) and (f) to produce a final alloy material;
and
(h) subjecting the final alloy material to a final heat treatment selected to provide the zirconium-based alloy exhibiting one of improved corrosion resistance and improved creep resistance,
wherein for providing the zirconium-based alloy exhibiting improved corrosion resistance, the final alloy material is subjected to a final heat treatment of partial recrystallization to produce an amount of recrystallization from about 0% to about 33% with the remainder being stress relief annealed, and
wherein for providing the zirconium-based alloy exhibiting improved creep resistance, the final alloy material is subjected to a final heat treatment of partial recrystallization to produce an amount of recrystallization from about 80% to about 100% recrystallization with the remainder being stress relief annealed.

17 more elements

A method of making a zirconium-based alloy which exhibits one of improved corrosion resistance and improved creep resistance for use in an elevated temperature environment of a nuclear reactor, comprising the steps:

(a) combining:
0.2 to 1.5 weight percent niobium;
0.01 to 0.6 weight percent iron;
0.0 to 0.8 weight percent tin;
0.0 to 0.5 weight percent chromium;
0.0 to 0.3 weight percent copper;
0.0 to 0.3 weight percent vanadium;
0.0 to 0.1 weight percent nickel;
and
a balance at least 97 weight percent zirconium, including impurities, to provide an alloy mixture;
(b) melting the alloy mixture to produce a melted alloy material;
(c) forging the melted alloy material to produce a forged alloy material;
(d) quenching the forged alloy material to produce a quenched alloy material;
(e) extruding the quenched alloy material to produce a tube-shell alloy material;
(f) pilgering the tube-shell alloy material to produce a reduced tube-shell alloy material;
(g) annealing the tube-shell alloy material to produce an annealed alloy material;
(h) repeating steps (f) and (g) to produce a final alloy material;
and
(i) subjecting the final alloy material to a final heat treatment selected to provide a zirconium-based alloy exhibiting one of improved corrosion resistance and improved creep resistance,
wherein for providing the zirconium-based alloy exhibiting improved corrosion resistance, the final alloy material is subjected to a final heat treatment of partial recrystallization to produce an amount of recrystallization from about 0% to 33% with the remainder being stress relief annealed, and
wherein for providing the zirconium-based alloy exhibiting improved creep resistance, the final alloy material is subjected to a final heat treatment of partial recrystallization to produce an amount of recrystallization from about 80% to 100% recrystallization with the remainder being stress relief annealed.

18 more elements

A zirconium-based alloy for use in an elevated temperature environment of a nuclear reactor, comprising an alloying composition:

0.2 to 1.5 weight percent niobium;
0.01 to 0.6 weight percent iron;
0.0 to 0.8 weight percent tin;
0.0 to 0.5 weight percent chromium;
0.0 to 0.3 weight percent copper;
0.0 to 0.3 weight percent vanadium;
0.0 to 0.1 weight percent nickel;
and
a balance at least 97 weight percent zirconium, including impurities, the zirconium-based alloy formed by a process, comprising:
(a) melting the alloying composition to produce a melted alloy material;
(b) forging the melted alloy material to produce a forged alloy material;
(c) quenching the forged alloy material to produce a quenched alloy material;
(e) rolling the quenched alloy material to produce a rolled alloy material;
(f) annealing the rolled alloy material to produce a conditioned alloy material;
(g) repeating steps (e) and/or (f) to produce a final alloy material;
and
(h) subjecting the final alloy material to a final heat treatment selected to provide the zirconium based alloy exhibiting one of improved corrosion resistance and improved creep resistance,
wherein for providing the zirconium-based alloy exhibiting improved corrosion resistance, the final alloy material is subjected to a final heat treatment of partial recrystallization to produce an amount of recrystallization from about 0% to about 33% with the remainder being stress relief annealed, and
wherein for providing the zirconium-based alloy exhibiting improved creep resistance, the final alloy material is subjected to a final heat treatment of partial recrystallization to produce an amount of recrystallization from about 80% to about 100% recrystallization with the remainder being stress relief annealed.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/791,934Filed 6 Jul 2015
Priority: 23 Mar 2004
Published: 29 Oct 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

C22F 1/186
High-melting or refractory metals or alloys based thereon: of zirconium or alloys based thereon
C21D 1/26
General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering: methods of annealing
C21D 7/13
Modifying the physical properties of iron or steel by deformation: by hot working
C22C 16/00
Alloys based on zirconium

Family

Application60/555,600Us provisional application · filed 23 Mar 2004
Application60/564,416Us provisional application · filed 22 Apr 2004
Application60/564,417Us provisional application · filed 22 Apr 2004
Application60/564,469Us provisional application · filed 22 Apr 2004
Application11/087,844Division · filed 23 Mar 2005
Application12/697,322Continuation in part · filed 1 Feb 2010
Application13/161,563Division · filed 16 Jun 2011
Application14/745,792Continuation in part · filed 22 Jun 2015
Application14/791,934Continuation in part
Application14/745,792Division
Application13/161,563Continuation in part
Application12/697,322Division
US 10,221,475 B2Related patent
US 2006/0243358 A1Published application
US 2010/0128834 A1Published application
US 2011/0293466 A1Published application
US 2015/0337425 A1Published application
US 9,284,629 B2Related patent
US 9,725,791 B2Related patent
US 2015/0307976 A1This patent

From the US filing history. Foreign family members aren’t listed.