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A method of welding alloys having directionally-solidified grain structure. The methods improve the weldability of these alloys by creating a localized region of fine grain structure, wherein the welding occurs in these localized regions. The localized regions are formed by applying strain energy us

A method of welding alloys having directionally-solidified grain structure. The methods improve the weldability of these alloys by creating a localized region of fine grain structure, wherein the welding occurs in these localized regions. The localized regions are formed by applying strain energy using a variety of different methods, such as by hammer peening, laser peening or sand blasting. Then, a heat treatment step may be used to create recrystallized grains having the fine grain structure. The region of fine grain structure provides better weldability.

대표청구항 ▼

1. A method for welding alloys having a directionally-solidified grain structure comprising: breaking down a portion of the directionally-solidified grain structure in an area to be welded;recrystallizing grains in the portion of the directionally-solidified grain structure in the area to be welded

1. A method for welding alloys having a directionally-solidified grain structure comprising: breaking down a portion of the directionally-solidified grain structure in an area to be welded;recrystallizing grains in the portion of the directionally-solidified grain structure in the area to be welded to form a localized region of grains having a fine grain structure, andwelding the alloys in the localized region of grains having a fine grain structure. 2. The method of claim 1, wherein energy is applied to break down the portion of the directionally-solidified gram structure in the area to be welded. 3. The method of claim 2, wherein strain energy is applied to break down the portion of the directionally-solidified grain structure in the area to be welded. 4. The method of claim 3, wherein the strain energy is applied using a method selected from hammer peening, shot peening, laser peening, grit and sand blasting, or a combination thereof. 5. The method of claim 3, wherein the strain energy is applied in an amount sufficient to cause plastic deformation of the directionally-solidified grains in the area to be welded. 6. The method of claim 1, wherein the grains in the portion of the directionally-solidified grain structure in the area to be welded are recrystallized using a heat treatment step. 7. The method of claim 6, wherein the heat treatment step is selected from mill anneal, recrystallize anneal, solution treatment and aging, or a combination thereof. 8. The method of claim 1, wherein fusion welding is used for welding the alloys in the localized region of grains having a fine grain structure. 9. The method of claim 8, wherein the fusion welding is selected from arc welding, electron beam welding, flash welding, laser welding, or a combination thereof. 10. A method for repairing a turbine component having a directionally-solidified grain structure in at least a portion of the turbine component comprising: breaking down a portion of the directionally-solidified grain structure in the turbine component;recrystallizing grains in the portion of the directionally-solidified grain structure in the turbine component to form a localized region of grains having a fine grain structure; andwelding the localized region of grains having a fine grain structure. 11. The method of claim 10, wherein energy is applied to break down the portion of the directionally-solidified grain structure in the turbine component. 12. The method of claim 11, wherein strain energy is applied to break down the portion of the directionally-solidified grain structure in the turbine component. 13. The method of claim 12, wherein the strain energy is applied using a method selected from hammer peening, shot peening, laser peening, grit and sand blasting, or a combination thereof. 14. The method of claim 12, wherein the strain energy is applied in an amount sufficient to cause plastic deformation of the directionally-solidified grains in the portion of the turbine component. 15. The method of claim 10, wherein the grains in the portion of the directionally-solidified grain structure in the turbine component are recrystallized using a heat treatment step. 16. The method of claim 15, wherein the heat treatment step is selected from mill anneal, recrystallize anneal, solution treatment and aging, or a combination thereof. 17. The method of claim 10, wherein fusion welding is used for repairing the turbine component. 18. The method of claim 17, wherein the fusion welding is selected from arc welding, electron beam welding, flash welding, laser welding, or a combination thereof.