Welded joint of duplex stainless steel
View Patent ↗A welded joint of duplex stainless steel, which can suppress precipitation σ phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments. A weld metal of the welded joint contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: at most 2.00%, Ni: 7.00 to 12.00%, Cr: 20.0 to 30.0%, Mo: 1 to 4%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, and O: at most 0.035%, the balance being Fe and impurities. The weld metal satisfies Expressions (1) and (3): 2.2Cr+7Mo+3Cu>66 (1) Cr+11Mo+10Ni−12(Cu+30N)<100 (3) where a content (mass percent) of each element in one of the base metal and weld metal is used for each element in Expressions (1) and (3).
1. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni: more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1) and Expression (3):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
2. The joint of duplex stainless steel according to claim 1 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
3. The joint of duplex stainless steel according to claim 2 , wherein the Mo content of the base metal is 1.10 to 2.00%.
4. The joint of duplex stainless steel according to claim 1 , wherein the Mo content of the base metal is 1.10 to 2.00%.
5. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni: more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, and V at most 1.50%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1) and Expression (3):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
6. The joint of duplex stainless steel according to claim 5 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
7. The joint of duplex stainless steel according to claim 6 , wherein the Mo content of the base metal is 1.10 to 2.00%.
8. The joint of duplex stainless steel according to claim 5 , wherein the Mo content of the base metal is 1.10 to 2.00%.
9. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni: more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, and at least one type selected from the group consisting of Ca: at most 0.0200%, Mg: at most 0.0200%, and B: at most 0.0200%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1) and Expression (3):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
10. The joint of duplex stainless steel according to claim 9 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
11. The joint of duplex stainless steel according to claim 10 , wherein the Mo content of the base metal is 1.10 to 2.00%.
12. The joint of duplex stainless steel according to claim 9 , wherein the Mo content of the base metal is 1.10 to 2.00%.
13. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni: more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, and rare earth metal: at most 0.2000%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1 ) and Expression (3 ):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3),
wherein the joint has an area fraction of a sigma phase, which is less than 1%.
14. The joint of duplex stainless steel according to claim 13 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
15. The joint of duplex stainless steel according to claim 14 , wherein the Mo content of the base metal is 1.10 to 2.00%.
16. The joint of duplex stainless steel according to claim 13 , wherein the Mo content of the base metal is 1.10 to 2.00%.
17. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni:
more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, V: at most 1.50%, instead of part of the Fe, and at least one type selected from the group consisting of Ca: at most 0.0200%, Mg: at most 0.0200%, and B: at most 0.0200%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1 ) and Expression (3 ):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
18. The joint of duplex stainless steel according to claim 17 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
19. The joint of duplex stainless steel according to claim 18 , wherein the Mo content of the base metal is 1.10 to 2.00%.
20. The joint of duplex stainless steel according to claim 17 , wherein the Mo content of the base metal is 1.10 to 2.00%.
21. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni: more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, V: at most 1.50%, instead of part of the Fe, and rare earth metal: at most 0.2000%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1) and Expression (3):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
22. The joint of duplex stainless steel according to claim 21 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
23. The joint of duplex stainless steel according to claim 22 , wherein the Mo content of the base metal is 1.10 to 2.00%.
24. The joint of duplex stainless steel according to claim 21 , wherein the Mo content of the base metal is 1.10 to 2.00%.
25. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni:
more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, V: at most 1.50%, instead of part of the Fe, rare earth metal: at most 0.2000%, instead of part of the Fe, and at least one type selected from the group consisting of Ca: at most 0.0200%, Mg: at most 0.0200%, and B: at most 0.0200%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1) and Expression (3):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
26. The joint of duplex stainless steel according to claim 25 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
27. The joint of duplex stainless steel according to claim 26 , wherein the Mo content of the base metal is 1.10 to 2.00%.
28. The joint of duplex stainless steel according to claim 25 , wherein the Mo content of the base metal is 1.10 to 2.00%.
29. A joint of duplex stainless steel comprising:
a base metal; and
a weld metal, wherein
the base metal consists of, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities,
the base metal satisfies Expression (1) and Expression (2),
the weld metal contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.010%, Cu: 0.10 to 0.8%, Ni: more than 8.00 and at most 12.00%, Cr: 20.0 to 30.0%, Mo: 1.00 to 4.00%, N: 0.100to 0.350%, sol. Al: at most 0.040%, O: at most 0.035%, rare earth metal: at most 0.2000%, instead of part of the Fe, and at least one type selected from the group consisting of Ca: at most 0.0200%, Mg: at most 0.0200%, and B: at most 0.0200%, the balance being Fe and impurities, and
the weld metal satisfies Expression (1) and Expression (3):
2.2Cr+7Mo+3Cu>66 (1)
Cr+11Mo+10Ni−12(Cu+30N)<0 (2)
Cr+11Mo+10Ni−12(Cu+30N)<100 (3)
where a content (mass percent) of each element in one of the base metal and the weld metal is substituted into a symbol of each element in Expression (1) to Expression (3), wherein the joint has an area fraction of a sigma phase, which is less than 1%.
30. The joint of duplex stainless steel according to claim 29 , wherein
the weld metal further contains W: at most 4.00%, instead of part of the Fe.
31. The joint of duplex stainless steel according to claim 30 , wherein the Mo content of the base metal is 1.10 to 2.00%.
32. The joint of duplex stainless steel according to claim 29 , wherein the Mo content of the base metal is 1.10 to 2.00%.