Weld metal having excellent resistance to hydrogen embrittlement susceptibility

Patent metadata

Field	Value
Publication number	US-9592575-B2
Application number	US-201214110556-A
Country	US
Kind code	B2
Filing date	Apr 6, 2012
Priority date	Apr 8, 2011
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

The weld metal of the present invention is formed by gas shield arc welding using a flux-cored wire, has a predetermined chemical component composition, and contains 20% or more of Ti. The amount of Ti-containing oxide particles having a circle-equivalent diameter of 0.15-1.0 μm is at least 5000 per square mm, the amount of V per total mass of weld metal present as a compound within the weld metal is 0.002% or more, and the average circle equivalent diameter of V-containing carbide present in the weld metal is 15 nm or less.

First claim

The invention claimed is:

1. A weld metal comprising;
C: 0.02 to 0.12% (means “mass %” which is identical here and hereinafter for the chemical component composition), Si: 0.1 to 0.80%, Mn: 0.9 to 2.5%, Ni: 0.20 to 3.5%, Mo: 0.05 to 1.50%, Ti: 0.040 to 0.15%, V: 0.05 to 0.60%, N: 0.015% or less, not including 0%, and O: 0.030% or more respectively, with the balance of iron and unavoidable impurities, wherein
Ti-containing oxide particles containing Ti by 20% or more, and having a circle equivalent diameter of 0.15 to 1.0 μm are present by the number of 5,000/mm 2 or more, and the amount of V per total mass of the weld metal present as a compound in the weld metal is 0.002% or more and, further,
an average circle equivalent diameter of the V-containing carbide present in the weld metal is 15 nm or less.

2. The weld metal of claim 1 , further containing at least one of the following elements:
Cr: 2.0% or less (not including 0%),
Nb: 0.15% or less (not including 0%)
Cu: 1.0% or less (not including 0%),
Al: 0.020% of less (not including 0%)
Zr: 0.10% or less (not including 0%), and
B: 0.0050% or less (not including 0%).

3. The weld metal of claim 1 , wherein the Ti-containing oxide particles containing Ti by 20% or more, and having a circle equivalent diameter of 0.15 to 1.0 μm are present by the number of 5,000/mm 2 to 40,000/mm 2 .

4. The weld metal of claim 1 , wherein the Ti-containing oxide particles containing Ti by 20% or more, and having a circle equivalent diameter of 0.15 to 1.0 μm are present by the number of 5,000/mm 2 to 30,000/mm 2 .

5. The weld metal of claim 1 , wherein the Ti-containing oxide particles containing Ti by 20% or more, and having a circle equivalent diameter of 0.15 to 1.0 μm are present by the number of 5,000/mm 2 to 20,000/mm 2 .

6. The weld metal of claim 1 , wherein the amount of V per total mass of the weld metal present as a compound in the weld metal is 0.002% to 0.05%.

7. The weld metal of claim 1 , wherein the average circle equivalent diameter of the V-containing carbides present in the weld metal is 12 nm or less.

8. The weld metal of claim 1 , wherein the average circle equivalent diameter of the V-containing carbides present in the weld metal is 10 nm or less.

9. The weld metal of claim 1 , wherein C is from 0.04 to 0.10%.

10. The weld metal of claim 1 , wherein Si is from 0.25 to 0.7%.

11. The weld metal of claim 1 , wherein Mn is from 1.2 to 2.2%.

12. The weld metal of claim 1 , wherein Ni is from 0.5 to 3.0%.

13. The weld metal of claim 1 , wherein Mo is from 0.1 to 1.0%.

14. The weld metal of claim 1 , wherein Ti is from 0.050 to 0.12%.

15. The weld metal of claim 1 , wherein V is from 0.1 to 0.6%.

16. The weld metal of claim 1 , wherein V is from 0.15 to 0.6%.

17. The weld metal of claim 1 , wherein N is 0.010% or less, not including 0%.

18. The weld metal of claim 1 , wherein 0 is from 0.030 to 0.10%.

19. The weld metal of claim 1 , wherein the unavoidable impurities are at least one selected form the group consisting of P, S ,and Sn.

20. The weld metal of claim 19 , wherein P is present in an amount that does not exceed 0.02% and S is present in an amount that does not exceed 0.025%.

Assignees

• Nako Hidenori
• Kochi Takuya
• Urushihara Wataru
• Sato Munenobu
• Kitagawa Yoshihiko
• Kobe Steel Ltd

Inventors

• Nako Hidenori
• Kochi Takuya
• Urushihara Wataru
• Sato Munenobu
• Kitagawa Yoshihiko

Classifications

• C22C38/46

  with vanadium · CPC title

• C22C38/04

  containing manganese · CPC title

• B23K35/0266

  flux-cored · CPC title

• B23K9/02

  Seam welding; Backing means; Inserts · CPC title

• B23K35/3066

  with Ni as next major constituent · CPC title