Method and repair insert for repairing metallic structure

• US 20110233293A1
• Filed: 03/26/2010
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Holland LP
• Original Assignee: Holland LP
• Inventors: Kral, Richard F., Mayhill, Shane A., Workman, David P.
• Granted Patent: US 8,651,393 B2
• Time in Patent Office: Days
• US Class Current: 238/122
• CPC Class Codes: B23K 11/0013 welding for reasons other than joining, e.g. build up welding
• CPC Class Codes: B23K 11/004 Welding of a small piece to a great or broad piece
• CPC Class Codes: B23K 11/34 Preliminary treatment
• CPC Class Codes: B23K 2101/26 Railway- or like rails
• CPC Class Codes: B23P 6/00 Restoring or reconditioning objects straightening or restoring form of sheet metal, metal rods, metal tubes, metal profiles, or specific articles made therefrom B21D1/00, B21D3/00; repairing defective or damaged objects by casting techniques B22D19/10
• CPC Class Codes: E01B 29/42 Undetachably joining or fastening track components in or on the track, e.g. by welding, by gluing; Pre-assembling track components by gluing; Sealing joints with filling components E01B31/26 takes precedence; independent heating means E01B31/18; welding in general B23K; gluing metal parts in general F16B11/00
• CPC Class Codes: E01B 31/18 Reconditioning or repairing worn or damaged parts on the spot, e.g. applying inlays, building-up rails by welding E01B31/04 - E01B31/12 take precedence; Heating or cooling of parts on the spot, e.g. for reducing joint gaps, for hardening rails
• CPC Class Codes: Y10T 29/49728 and by a metallurgical operation, e.g., welding, diffusion bonding, casting

Abstract

A rail repair method and insert therefor enables repair of rails and rail-like structures. A rail defect is initially identified and removed as contained within a volumetric material portion so as to form a contoured void while maintaining continuity of the rail opposite the void. A pre-formed insert is then placed into the void thereby effecting a rail-to-insert interface. Current is driven through the interface as force directs the insert against the rail. Resistance heat and pressure weld the insert to the rail. The flash welding aspects remove oxides and other impurities from the interface, and the forge welding aspects create a robust solid state weld. Excess material, whether flash, rail, or insert-based, is removed during the finishing processes to provide a virtually seamless rail repair. The solid state weld repair insert and underlying methodology enabled thereby may be used to repair any number of targeted metallic rail-like structures.

Claims

1. A method of repairing a metallic structure having first and second structural sections, the method comprising the steps of:

a) identifying and locating a defect in the metallic structure;

b) removing a volumetric portion from the first structural section, the volumetric portion being inclusive of the defect;

c) exposing a void site in the first structural section via removal of the volumetric portion;

d) placing a pre-formed, solid state weld repair insert into the void site, thereby effecting a structure-to-insert interface; and

e) welding the metallic structure and insert at the structure-to-insert interface.

2. The method of claim 1 wherein the welding step comprises the step of driving current through the structure-to-insert interface.

3. The method of claim 1 comprising the step of maintaining continuity of the second structural section while exposing the void site.

4. The method of claim 3 wherein the volumetric portion has a first volume and the insert has a second volume greater in magnitude relative to the first volume.

5. The method of claim 4 comprising the step of forcing the insert against the metallic structure during the welding process.

6. The method of claim 5 comprising the step of removing oxides from the structure-to-insert interface during the welding process.

7. The method of claim 6 comprising the step of interdiffusing atomic structure from the metallic structure and insert across the structure-to-insert interface.

8. The method of claim 7 wherein the metallic structure is a rail.

9. A method of repairing a current-conductive rail, which rail includes upper and lower rail sections, the method comprising the steps of:

a) identifying and locating a defect in a first select rail section, the first select rail section being selected from the group consisting of the upper and lower rail sections;

b) removing a volumetric portion of the rail from the first select rail section, the volumetric portion being inclusive of the defect;

c) exposing a void site in the first select rail section via removal of the volumetric portion;

d) placing a pre-formed current-conductive insert into the void site, thereby effecting a rail-to-insert interface;

e) driving current through the rail-to-insert interface;

f) resistance-heating the rail and insert at the rail-to-insert interface via the driven current; and

g) welding the insert to the rail.

10. The method of claim 9 comprising the step of maintaining continuity of a second select rail section while exposing the void site, the second select rail section being selected from the group consisting of the upper and lower rail sections and being other than the first select rail section.

11. The method of claim 10 wherein the volumetric portion has a first volume and the insert has a second volume greater in magnitude relative to the first volume.

12. The method of claim 11 wherein the void site has a maximal transverse cross-sectional site area and the insert has a maximal transverse cross-sectional insert area, said insert area being greater in magnitude than said site area.

13. The method of claim 9 comprising the step of forcing the insert against the rail while driving current through the rail-to-insert interface.

14. The method of claim 9 comprising the step of removing oxides from the rail-to-insert interface.

15. The method of claim 13 comprising the step of interdiffusing atomic structure of the rail and insert across the rail-to-insert interface.

16. The method of claim 12 wherein said insert area is minimized relative to said site area.

17. A method of repairing a current-conductive rail, said method comprising the steps of:

a) removing a defect-inclusive, volumetric rail portion from said rail;

b) exposing a void site in said rail via removal of said rail portion;

c) placing a pre-formed current-conductive insert into the void site, thereby effecting a rail-to-insert interface; and

d) driving current through the rail-to-insert interface, thereby heating the rail and insert at the rail-to-insert interface and welding the insert to the rail.

18. The method of claim 17 comprising the step of maintaining continuity of the rail adjacent the void site while exposing the void site.

19. The method of claim 18 comprising the step of forcing the insert against the rail while driving current through the rail-to-insert interface, thereby

a. removing oxides from the rail-to-insert interface;

and

b. interdiffusing atomic structure of the rail and insert across the rail-to-insert interface.

20. A rail repair method, the method comprising the steps of:

forming a wedge-shaped repair insert having a pointed rail-opposing portion, the pointed rail-opposing portion having opposed planar insert surfaces, the opposed planar insert surfaces being substantially orthogonal to one another;

forming a wedge-shaped void in a rail, the void having a pointed, insert-receiving notch, the pointed insert-receiving notch having opposed planar void site surfaces, the void site surfaces being substantially orthogonal to one another;

inserting the wedge-shaped repair insert into the wedge-shaped void thereby effecting an angled rail-to-insert interface, the angled rail-to-insert interface thus having a 90 degree angle; and

driving current through the rail-to-insert interface for heating and welding the rail and insert at the rail-to-insert interface, the 90 degree angle for enhancing uniform heat distribution and minimizing material entrapment during the welding process.

21. The method of claim 20 wherein the current driving step comprises the steps of:

preheating the rail and repair insert by driving a first range of current therethrough;

flashing the rail and repair insert by driving a second range of current therethrough; and

forging the rail and repair insert by driving a third range of current therethrough.

22. The method of claim 21 wherein the repair insert forming step comprises the added step of forming a beveled tip intermediate the opposed planar insert surfaces and the void forming step comprises the added step of forming a beveled valley intermediate the opposed planar void site surfaces, the beveled tip and beveled valley for further minimizing material entrapment during the welding process.

23. A rail and repair insert combination, said combination comprising:

a rail length, the rail length having a rail head portion, a rail web portion, a rail base portion, and a void site, the void site being located intermediate the rail length and extending into the rail head portion, the void site having a maximal site depth and a maximal site length; and

a repair insert, the repair insert being insertable into the void site for effecting a rail-to-insert interface, the repair insert comprising an upper insert portion, a lower insert portion, a maximal insert depth, and a maximal insert length, said insert depth being greater in magnitude than said site depth, said insert length being greater in magnitude than said site length.

24. The combination of claim 23 wherein the rail and repair insert are formed from weldable materials, the rail and repair insert thus being weldable to one another.

25. The combination of claim 24 wherein the void site has a wedge-shaped, longitudinal site cross-section and the repair insert has a wedge-shaped, longitudinal insert cross-section.

26. The combination of claim 25 wherein said wedge-shaped longitudinal site and insert cross-sections comprise substantially 90 degree angles at the rail-to-insert interface.

27. The combination of claim 26 wherein said wedge-shaped longitudinal site and insert cross-sections respectively comprise a beveled valley and beveled tip.

28. The combination of claim 24 wherein the void site extends into the rail web portion.

29. The combination of claim 28 wherein the void site has a maximal transverse cross-sectional site area and the insert has a maximal transverse cross-sectional insert area, the insert area being greater in magnitude relative to the site area.

30. The combination of claim 29 wherein said insert area is minimized relative to said site area.

31. The combination of claim 30 wherein the upper insert portion has a substantially uniform upper insert portion width, the lower insert portion has a substantially uniform lower insert portion width, the rail head portion has a maximum head width, and the rail web portion has a substantially uniform web width, said upper insert portion width being greater in magnitude relative to said lower insert portion width and said head width, said lower insert portion width being lesser in magnitude than said head width and greater in magnitude than said web width.

32. The combination of claim 31 wherein the maximal transverse cross-sectional insert area is beveled intermediate said upper insert portion width and said lower insert portion width.

33. A solid state weld repair insert for use in repairing a targeted metallic structure having first and second structural sections and a void site formed therein, the void site extending into the first structural section and having a maximal site depth and a maximal site length, the repair insert being insertable into the void site for effecting a structure-to-insert interface, the repair insert comprising first and second insert portions, a maximal insert depth, and a maximal insert length, said insert depth being greater in magnitude than said site depth, said insert length being greater in magnitude than said site length.

34. The repair insert of claim 33 wherein the metallic structure and repair insert are formed from weldable materials, the metallic structure and repair insert thus being weldable to one another.

35. The repair insert of claim 34 wherein the void site of the metallic structure has a wedge-shaped, longitudinal site cross-section and the repair insert has a wedge-shaped, longitudinal insert cross-section.

36. The repair insert of claim 35 wherein said wedge-shaped longitudinal site and insert cross-sections comprise substantially 90 degree angles at the structure-to-insert interface for enhancing uniform heat distribution and minimizing material entrapment during the welding process.

37. The repair insert of claim 36 wherein said site and insert cross-sections respectively comprise a beveled valley and a beveled tip for further minimizing material entrapment during the welding process.

38. The repair insert of claim 34 wherein the void site is formed in a targeted rail structure having rail head, web, and base portions, the void site extending into the rail head and web portions.

39. The repair insert of claim 38 wherein the void site has a maximal transverse cross-sectional site area and the insert has a maximal transverse cross-sectional insert area, the insert area being greater in magnitude relative to the site area.

40. The repair insert of claim 39 wherein said insert area is minimized relative to said site area.

41. The repair insert of claim 40 wherein the first insert portion bas a substantially uniform first insert portion width, the second insert portion has a substantially uniform second insert portion width, the rail head has a maximum head width, and the rail web has a substantially uniform web width, said first insert portion width being greater in magnitude relative to said second insert portion width and said head width, said second insert portion width being lesser in magnitude than said head width and greater in magnitude than said web width.

42. The rail repair insert of claim 41 wherein the maximal transverse cross-sectional insert area is beveled intermediate said upper insert portion width and said lower insert portion width.