Thermite welding

Patent metadata

Field	Value
Publication number	US-10207359-B2
Application number	US-201615276230-A
Country	US
Kind code	B2
Filing date	Sep 26, 2016
Priority date	Apr 21, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A process for welding metallic sections that includes providing first and second metallic sections to be welded together, and wherein the welded rail sections will include a weld fusion zone that further includes a weld terminus at each rail section; providing thermite welding dies for use in welding the metallic sections together; covering the thermite welding dies with an oxide displacing or oxide dissolving flux added locally to the edges of the thermite welding dies that are immediately adjacent to the weld fusion zone and the metallic sections; positioning the thermite welding dies on the metallic sections in the region where the metallic sections are to be joined together; and initiating an exothermic reaction between the thermite welding dies and the metallic sections by introducing molten metal into the region where the metallic sections are to be joined together, wherein the exothermic reaction creates a weld between the metallic sections.

First claim

What is claimed:

1. A process for welding metallic sections, comprising:
(a) providing first and second metallic sections, wherein the first and second metallic sections are to be welded together, and wherein the first and second metallic sections include a weld fusion zone that further includes a weld terminus at each metallic section;
(b) providing thermite welding dies for use in welding the metallic sections together;
(c) covering the thermite welding dies with an oxide displacing or oxide dissolving flux, wherein the flux is added locally to the edges of the thermite welding dies that will be immediately adjacent to the weld fusion zone and the metallic sections;
(d) positioning the thermite welding dies on the metallic sections in the region where the metallic sections are to be joined together; and
(e) initiating an exothermic reaction between the thermite welding dies and the metallic sections by introducing molten metal into the region where the metallic sections are to be joined together, wherein the exothermic reaction creates a weld between the metallic sections.

2. The process of claim 1 , further comprising attaching the flux to the thermite welding dies using polyvinyl alcohol or polyethylene glycol.

3. The process of claim 1 , further comprising adding oxygen inside the thermite welding dies at the weld terminus or toe to locally create heat by iron oxidation.

4. The process of claim 1 , further comprising adding an oxidizer insert for improving flow in the thermite dies to promote heating in a predetermined area.

5. The process of claim 4 , wherein the oxidizer includes polyvinyl alcohol, polyethylene glycol, glycerin, and potassium nitrate.

6. The process of claim 1 , wherein the flux includes boron, silicon, manganese, carbon, or combinations thereof.

7. The process of claim 1 , wherein the flux is mechanically mixed or embedded into the thermite dies.

8. A process for welding rail sections, comprising:
(a) providing first and second rail sections, wherein the first and second rail sections are to be welded together, and wherein the welded rail sections include a weld fusion zone that further includes a weld terminus at each rail section;
(b) providing thermite welding dies for use in welding the rail sections together;
(c) covering the thermite welding dies with an oxide displacing or oxide dissolving flux, wherein the flux is added locally to the edges of the thermite welding dies that will be immediately adjacent to the weld fusion zone and the rail sections;
(d) positioning the thermite welding dies on the rail sections in the region where the rail sections are to be joined together; and
(e) initiating an exothermic reaction between the thermite welding dies and the rail sections by introducing molten metal into the region where the rail sections are to be joined together, wherein the exothermic reaction creates a weld between the rail sections.

9. The process of claim 8 , further comprising attaching the flux to the thermite welding dies using polyvinyl alcohol or polyethylene glycol.

10. The process of claim 8 , further comprising adding oxygen inside the thermite welding dies at the weld terminus or toe to locally create heat by iron oxidation.

11. The process of claim 8 , further comprising adding an oxidizer insert for improving flow in the thermite dies to promote heating in a predetermined area.

12. The process of claim 11 , wherein the oxidizer includes polyvinyl alcohol, polyethylene glycol, glycerin, and potassium nitrate.

13. The process of claim 8 , wherein the flux includes boron, silicon, manganese, carbon, or combinations thereof.

14. The process of claim 8 , wherein the flux is mechanically mixed or embedded into the thermite dies.

15. A process for welding rail sections, comprising:
(a) providing first and second rail sections, wherein the first and second rail sections are to be welded together, and wherein the welded rail sections include a weld fusion zone that further includes a weld terminus at each rail section;
(b) providing thermite welding dies for use in welding the rail sections together;
(c) adding an oxide displacing or oxide dissolving flux to the thermite welding dies, wherein the flux is added as an insert to the thermite welding dies to cover the weld terminus at each rail section;
(d) positioning the thermite welding dies on the rail sections in the region where the rail sections are to be joined together; and
(e) initiating an exothermic reaction between the thermite welding dies and the rail sections by introducing molten metal into the region where the rail sections are to be joined together, wherein the exothermic reaction creates a weld between the rail sections.

16. The process of claim 15 , further comprising adding oxygen inside the thermite welding dies at the weld terminus or toe to locally create heat by iron oxidation.

17. The process of claim 15 , further comprising adding an oxidizer insert for improving flow in the thermite dies to promote heating in a predetermined area.

18. The process of claim 17 , wherein the oxidizer includes polyvinyl alcohol, polyethylene glycol, glycerin, and potassium nitrate.

19. The process of claim 15 , wherein the flux includes boron, silicon, manganese, carbon, or combinations thereof.

Assignees

• Edison Welding Inst Inc

Inventors

• Workman David P
• Shira Seth C

Classifications

• B23K1/0006

  Exothermic brazing · CPC title

• B23K20/165

  involving an exothermic reaction of the interposed material · CPC title

• B23K35/3613

  Polymers, e.g. resins · CPC title

• B23K35/3601

  with inorganic compounds as principal constituents · CPC title

• B23K23/00 Primary

  Alumino-thermic welding · CPC title