Claims

1. A forged component formed of an austenitic stainless steel alloy comprising, by weight:18.0 to 22.0% chromium;8.0 to 14.0% nickel;4.0 to 7.0% manganese;0.4 to 0.6% silicon;at least 0.2 up to 1.0% nitrogen;at least 0.05 up to 0.075% carbon;up to 0.3% molybdenum;up to 1.0% niobium;up to 0.2% cobalt;up to 4.5% aluminum;up to 0.1% boron;up to 0.1% vanadium;up to 1.0% tungsten; andup to 5.0% copper;the balance being iron and incidental impurities.

2. The forged component according to claim 1, wherein nitrogen is present in the alloy in a range of 0.2 to 0.6 weight percent.

3. The forged component according to claim 1, wherein nitrogen is present in the alloy in a range of 0.2 to 0.4 weight percent.

4. The forged component according to claim 1, wherein niobium is present in the alloy in an amount to yield a niobium:carbon ratio of at least 10:1 by weight percent.

5. The forged component according to claim 1, wherein niobium is present in the alloy in a range of 0.5 to 1.0 weight percent.

6. The forged component according to claim 1, wherein the component is a component of a gas turbine engine shroud assembly.

7. The forged component according to claim 1, wherein the component has a microstructure that is fully austenitic, contains stable carbides including niobium carbides, and does not contain delta ferrite or segregation.

8. The forged component according to claim 1, wherein the austenitic stainless steel alloy consists of 18.0 to 22.0% chromium, 8.0 to 14.0% nickel, 4.0 to 7.0% manganese, 0.4 to 0.6% silicon, at least 0.2 up to 1.0% nitrogen, at least 0.05 up to 0.075% carbon, up to 0.3% molybdenum, up to 1.0% niobium, up to 0.2% cobalt, up to 4.5% aluminum, up to 0.1% boron, up to 0.1% vanadium, up to 1.0% tungsten, up to 5.0% copper, the balance iron and incidental impurities.

9. The forged component according to claim 8, wherein the component is a component of a gas turbine engine shroud assembly.

10. The forged component according to claim 8, wherein the component has a microstructure that is fully austenitic, contains stable carbides including niobium carbides, and does not contain delta ferrite or segregation.

11. A process of producing a forged component formed of an austenitic stainless steel alloy comprising, by weight, 18.0 to 22.0% chromium, 8.0 to 14.0% nickel, 4.0 to 7.0% manganese, 0.4 to 0.6% silicon, at least 0.2 up to 1.0% nitrogen, at least 0.5 up to 0.075% carbon, up to 0.3% molybdenum, up to 1.0% niobium, up to 0.2% cobalt, up to 4.5% aluminum, up to 0.1% boron, up to 0.1% vanadium, up to 1.0% tungsten, and up to 5.0% copper, with the balance iron and incidental impurities; the process comprising:preparing a melt of the alloy;forming an ingot/billet of the alloy;forging the ingot/billet to form the forged component;solution heat treating the forged component; and thenquenching the forged component.

12. The process according to claim 11, wherein nitrogen is present in the alloy in a range of 0.2 to 0.6 weight percent.

13. The process according to claim 11, wherein nitrogen is present in the alloy in a range of 0.2 to 0.4 weight percent.

14. The process according to claim 11, wherein niobium is present in the alloy in an amount to yield a niobium:carbon ratio of at least 10:1 by weight percent.

15. The process according to claim 11, wherein niobium is present in the alloy in a range of 0.5 to 1.0 weight percent.

16. The process according to claim 11, wherein the component is a component of a gas turbine engine shroud assembly.

17. The process according to claim 11, wherein the component has a microstructure that is fully austenitic, contains stable carbides including niobium carbides, and does not contain delta ferrite or segregation.

18. The process according to claim 11, wherein the solution heat treating step is performed at a temperature of about 1070 to about 1200° C., and the quenching step is sufficiently rapid to form a fully austenitic microstructure with stable carbides.

19. The process according to claim 11, wherein the component is a component of a gas turbine engine shroud assembly, and wherein the austenitic stainless steel alloy consists of 18.0 to 22.0% chromium, 8.0 to 14.0% nickel, 4.0 to 7.0% manganese, 0.4 to 0.6% silicon, at least 0.2 up to 1.0% nitrogen, at least 0.05 up to 0.075% carbon, up to 0.3% molybdenum, up to 1.0% niobium, up to 0.2% cobalt, up to 4.5% aluminum, up to 0.1% boron, up to 0.1% vanadium, up to 1.0% tungsten, up to 5.0% copper, the balance iron and incidental impurities.

20. The process according to claim 19, wherein the solution heat treating step is performed at a temperature of about 1070 to about 1200° C., and the quenching step is sufficiently rapid to form a fully austenitic microstructure that contains stable carbides including niobium carbides and does not contain delta ferrite or segregation.