Method of reheating rail weld zone

Patent metadata

Field	Value
Publication number	US-10144983-B2
Application number	US-201214119819-A
Country	US
Kind code	B2
Filing date	May 23, 2012
Priority date	May 25, 2011
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A method of reheating a rail weld zone after rails were welded, a distance C between a reheating region P of a rail web portion 2 and a welding center Q is set to more than or equal to 0.2 times and less than or equal to three times a HAZ length Lh of the rail weld zone. A length B of the reheating region P may be more than or equal to 0.5 times and less than or equal to five times the HAZ length Lh of the rail weld zone. A height A of the reheating region P may be more than or equal to 0.2 times a height Hw of the rail web portion 2. A temperature Th reached in a reheating process at a center of the reheating region P may be higher than or equal to 400° C. and lower than or equal to 750° C.

First claim

The invention claimed is:

1. A method of reheating a rail weld zone, the method being performed after rails were welded, comprising:
selecting a distance Cw from a welding center Q as a location of a reheating region Pw of a rail web portion, the distance Cw being more than or equal to 0.2 times and less than or equal to three times a heat affected zone (HAZ) length Lh of the rail weld zone,
selecting a distance Ch in a rail longitudinal direction from a vertical axis through the welding center Q as a location of a reheating region Ph of a rail head top portion, wherein the distance Ch is more than or equal to 0.2 times and less than or equal to three times the HAZ length Lh of the rail weld zone, and
reheating the reheating region Pw simultaneously with the reheating region Ph based on the selected distances Cw and Ch.

2. The method of reheating a rail weld zone according to claim 1 ,
wherein the reheating region Ph of the rail head-top portion has a length Bh of more than or equal to 0.5 times and less than or equal to five times the HAZ length Lh of the rail weld zone.

3. The method of reheating a rail weld zone according to claim 1 ,
wherein the reheating region Ph of the rail head-top portion has a width Ah of more than or equal to 0.3 times a rail head width Gh.

4. The method of reheating a rail weld zone according to claim 1 ,
wherein the reheating region Ph of the rail head-top portion has a temperature Th(° C.) reached at a center of the reheating region Ph of higher than or equal to 400° C. and lower than or equal to 750° C.

5. The method of reheating a rail weld zone according to claim 1 ,
wherein the reheating region Pw has a length B in a rail longitudinal direction of more than or equal to 0.5 times and less than or equal to five times the HAZ length Lh of the rail weld zone:
0.5Lh≤B≤5Lh.

6. The method of reheating a rail weld zone according to claim 1 ,
wherein the reheating region Pw has a height A of more than or equal to 0.2 times a height Hw of the rail web portion:
0.2Hw≤A.

7. The method of reheating a rail weld zone according to claim 1 ,
wherein the reheating region Pw has a temperature Th(° C.) reached in a reheating process at a center of the reheating region Pw of higher than or equal to 400° C. and lower than or equal to 750° C.

8. The method of reheating a rail weld zone according to claim 7 , wherein the temperature Th(° C.) reached in the reheating process at the center of the reheating region Pw satisfies the following Expression (1)
0.375 Tw+ 350 ≤Th≤ 0.5 Tw+ 600  (1)

where Tw represents an initial temperature Tw(° C.) of the rail weld zone in the reheating process.

9. The method of reheating a rail weld zone according to claim 1 ,
further comprising a distance Cb between a reheating region Pb of a rail sole portion and the welding center Q that is more than or equal to 0.2 times and less than or equal to three times the HAZ length Lh of the rail weld zone.

10. A method of reheating a rail weld zone, the method being performed after rails were welded, comprising:
selecting a distance Cw from a welding center Q as a location of a reheating region Pw of a rail web portion, the distance Cw being more than or equal to 0.2 times and less than or equal to three times a heat affected zone (HAZ) length Lh of the rail weld zone,
selecting a distance Cb in a rail longitudinal direction from a vertical axis through the welding center Q as a location of a reheating region Pb of a rail sole portion, wherein the distance Cb is more than or equal to 0.2 times and less than or equal to three times the HAZ length Lh of the rail weld zone, and
reheating the reheating region Pw simultaneously with the reheating region Pb based on the selected distances Cw and Cb.

11. The method of reheating a rail weld zone according to claim 10 ,
wherein the reheating region Pb of the rail sole portion has a length Bb of more than or equal to 0.5 times and less than or equal to five times the HAZ length Lh of the rail weld zone.

12. The method of reheating a rail weld zone according to claim 11 ,
wherein the reheating region of the rail sole portion has a width Ab of more than or equal to 0.3 times a rail foot width Gb.

13. The method of reheating a rail weld zone according to claim 10 ,
wherein the reheating region Pb of the rail sole portion has a temperature Th(° C.) reached at a center of the reheating region Pb of higher than or equal to 400° C. and lower than or equal to 750° C.

14. The method of reheating a rail weld zone according to claim 10 ,
wherein the reheating region Pw has a length B in a rail longitudinal direction of more than or equal to 0.5 times and less than or equal to five times the HAG length Lh of the rail weld zone:
0.5Lh≤B≤5Lh.

15. The method of reheating a rail weld zone according to claim 10 ,
wherein the reheating region Pw has a height A of more than or equal to 0.2 times a height Hw of the rail web portion:
0.2Hw≤A.

16. The method of reheating a rail weld zone according to claim 10 ,
wherein the reheating region Pw has a temperature Th(° C.) reached in a reheating process at a center of the reheating region Pw of higher than or equal to 400° C. and lower than or equal to 750° C.

17. The method of reheating a rail weld zone according to claim 16 , wherein the temperature Th(° C.) reached in the reheating process at the center of the reheating region Pw satisfies the following Expression (1)
0.375 Tw+ 350 ≤Th≤ 0.5 Tw+ 600  (1)

where Tw represents an initial temperature Tw(° C.) of the rail weld zone in the reheating process.

Assignees

• Karimine Kenichi
• Ueda Masaharu
• Iwano Katsuya
• Tottori Hideo
• Yamamoto Takeshi
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Karimine Kenichi
• Ueda Masaharu
• Iwano Katsuya
• Tottori Hideo
• Yamamoto Takeshi

Classifications

• B23K2103/04

  Steel {or steel} alloys · CPC title

• C21D9/50

  for welded joints · CPC title

• C21D2221/00

  Treating localised areas of an article · CPC title

• B23K31/02

  relating to soldering or welding · CPC title

• C22C38/18

  containing chromium · CPC title