Method for post-weld heat treatment of welded components made of gamma prime strengthened superalloys
View Patent ↗A method for post-weld heat treatment of a without a filler material welded high strength component made of a gamma prime (γ′) strengthened superalloy can include providing the welded component, heating the welded component by applying a rapid heating-up rate in the range of 20° C./min to 40° C./min during the entire temperature range from room temperature (RT) up to a temperature T 1 of at least 1000° C., holding the welded component at T 1 and then heating the component by applying a slow heating-up rate of about 5° C./min to a final temperature T f , then holding the welded component at T f for a time t f sufficient for at least partially dissolving the gamma prime phase in a weld of the welded component and also in a base material surrounding the weld, and cooling the component with a cooling rate that is greater than or equal to about 20° C./min.
1. A method for post-weld heat treatment of a without a filler material welded high strength component made of a gamma prime (γ′) strengthened superalloy comprised of Ni or Co or Fe or combinations thereof, the method consisting of the following steps:
a) providing the welded component, then
b) heating the welded component by applying a rapid heating-up rate in the range of about 20° C./m in to 40° C./min during the entire temperature range from room temperature (RT) up to a temperature T 1 of at least 1000° C., then
c) holding the welded component at T 1 and then heating the component by applying a slow heating-up rate of about 5° C./min to a final temperature T f , then
d) holding the welded component at T f for a time t f sufficient for at least partially dissolving the gamma prime phase in the weld and also in a base material surrounding the weld, then
e) cooling the component with a cooling rate of about 20° C./min, and
f) finally optionally applying a precipitation hardening treatment.
2. The method according to claim 1 , wherein the rapid heating-up rate according to step b) is high enough to avoid gamma prime precipitations in a weld of the welded component.
3. The method according to claim 2 , wherein the rapid heating-up rate is about 25° C./min to 40° C./min.
4. The method according to claim 3 , wherein the rapid heating-up rate is about 25° C./min to 35° C./min.
5. The method according to claim 2 , wherein the rapid heating-up rate is about 20° C./min to 30° C./min.
6. The method according to claim 1 , wherein the cooling rate according to step e) is 20° C./min.
7. The method according to claim 1 , wherein said method is used for repairing components.
8. The method according to claim 1 , wherein said method is used for joined new parts/components.
9. The method according to claim 1 , wherein the welded component is welded by electron beam welding.
10. The method according to claim 1 , wherein the welded component is welded by laser welding.
11. The method according to claim 1 , wherein the precipitation hardening treatment is applied.
12. The method according to claim 1 , wherein the applying of the precipitation hardening treatment is performed such that the welded component is held at 850° C. for a precipitation hardening treatment time period.
13. The method according to claim 1 , wherein the rapid heating-up rate according to step b) is high enough to minimize gamma prime precipitations in a weld of the welded component.
14. The method according to claim 1 , wherein the holding of the welded component at T f for the time t f is holding the welded component for an isothermal dwell time.
15. The method according to claim 1 , wherein the providing of the welded component comprises electron beam welding a component of a turbine or laser welding a component of a turbine.
16. The method according to claim 1 , wherein T 1 is 1100° C.
17. The method according to claim 1 , wherein T f is 1140° C.
18. The method of claim 1 , wherein the cooling of the component with a cooling rate of about 20° C./min is performed until the component is at a precipitation hardening treatment temperature.
19. The method of claim 18 , wherein the applying of the precipitation hardening treatment is performed at the precipitation hardening treatment temperature for a precipitation hardening treatment time period.
20. A method for post-weld heat treatment of a without a filler material welded high strength component made of a gamma prime (γ′) strengthened superalloy comprised of Ni or Co or Fe or combinations thereof, the method comprising:
a) providing the welded component,
b) heating the welded component by applying a rapid heating-up rate in the range of 20° C./m in to 40° C./m in during the entire temperature range from room temperature (RT) up to a temperature T 1 of at least 1000° C.,
c) holding the welded component at T 1 and then heating the component by applying a slow heating-up rate of about 5° C./min to a final temperature T f , then
d) holding the welded component at T f for a time t f sufficient for at least partially dissolving the gamma prime phase in a weld of the welded component and also in a base material surrounding the weld, and
e) cooling the component with a cooling rate that is greater than or equal to about 20° C./min.