Treated turbine diaphragm and method for treating a turbine diaphragm

1. A method for treating a turbine diaphragm, comprising:

removing a portion of the turbine diaphragm;

forming a coupon having a geometry that corresponds to the portion of the turbine diaphragm that has been removed; and

joining the coupon to the turbine diaphragm,

wherein at least a portion of the coupon is a pre-sintered preform comprising a first homogenous formation of a first material having a first melting point and a second material having a second melting point, the first melting point being higher than the second melting point, and

wherein the turbine diaphragm is a gas turbine diaphragm.

2. The method of claim 1 , wherein the portion of the turbine diaphragm includes cast iron.

3. The method of claim 1 , wherein the portion of the turbine diaphragm includes a material selected from the group consisting of nodular iron, stainless steel and combinations thereof.

4. The method of claim 1 , wherein the removing is selected from the group consisting of grinding, machining, scraping, and combinations thereof.

5. The method of claim 1 , wherein the joining is selected from the group consisting of mechanical joining, brazing, and combinations thereof.

6. The method of claim 1 , further comprising cleaning the turbine diaphragm after removing the portion of the turbine component.

7. The method of claim 1 , further comprising heating the turbine diaphragm in furnace.

8. A treated turbine diaphragm, comprising:

a substrate; and

a coupon joined to the substrate,

wherein at least a portion of the coupon is a pre-sintered preform comprising a first homogenous formation of a first material having a first melting point and a second material having a second melting point, the first melting point being higher than the second melting point, and

wherein the treated turbine diaphragm is a gas turbine diaphragm.

9. The treated turbine diaphragm of claim 8 , wherein the substrate includes cast iron.

10. The treated turbine diaphragm of claim 8 , wherein the substrate includes a material selected from the group consisting of nodular iron, stainless steel and combinations thereof.

11. The treated turbine diaphragm of claim 8 , wherein the coupon is entirely the pre-sintered preform.

12. The treated turbine diaphragm of claim 8 , wherein the coupon includes both the pre-sintered preform and a top portion having a higher melting point than the pre-sintered preform, the pre-sintered preform being arranged and disposed between the top portion and the substrate.

13. The treated turbine diaphragm of claim 8 , wherein the pre-sintered preform further comprises a lower side of the pre-sintered preform having a higher proportion of the second material than in the first homogenous formation, the first homogenous formation and the lower side defining a bi-layer formation.

14. The treated turbine diaphragm of claim 12 , wherein the top portion is the same material as the substrate.

15. The treated turbine diaphragm of claim 8 , wherein the pre-sintered preform is a flexible pre-sintered preform.

16. The treated turbine diaphragm of claim 8 , wherein the pre-sintered preform is a rigid pre-sintered preform.

17. The treated turbine diaphragm of claim 8 , further including a mechanical joint joining the coupon to the substrate.

18. The treated turbine diaphragm of claim 8 , further including a braze joint joining the coupon to the substrate.

19. The treated turbine diaphragm of claim 8 , wherein the substrate is a seal rail of the turbine diaphragm.

20. The treated turbine diaphragm of claim 8 , wherein the coupon includes a geometry that corresponds to a portion of a turbine diaphragm which has been removed from the turbine diaphragm such that the replacement of the portion of the turbine diaphragm with the coupon forms the treated turbine diaphragm.