Ferritic stainless steel

Patent metadata

Field	Value
Publication number	US-9487849-B2
Application number	US-201214360192-A
Country	US
Kind code	B2
Filing date	Nov 28, 2012
Priority date	Nov 30, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

The invention provides ferritic stainless steels exhibiting good weldability and excellent corrosion resistance even under such welding conditions that sensitization is induced. The ferritic stainless steel includes, by mass %, C: 0.001 to 0.030%, Si: more than 0.3 to 0.55%, Mn: 0.05 to 0.50%, P: not more than 0.05%, S: not more than 0.01%, Cr: 19.0 to 28.0%, Ni: 0.01 to less than 0.30%, Mo: 0.2 to 3.0%, Al: more than 0.08 to 1.2%, V: 0.02 to 0.50%, Cu: less than 0.1%, Nb: 0.005 to 0.50%, Ti: 0.05 to 0.50%, and N: 0.001 to 0.030%, the balance being Fe and inevitable impurities, the ferritic stainless steel satisfying Equations (1) and (2).

First claim

The invention claimed is:

1. A ferritic stainless steel comprising, by mass %, C: 0.001 to 0.030%, Si: more than 0.3 to 0.55%, Mn: 0.05 to 0.50%, P: not more than 0.05%, S: not more than 0.01%, Cr: 19.0 to 28.0%, Ni: 0.01 to less than 0.30%, Mo: 0.2 to 3.0%, Al: more than 0.08 to 1.2%, V: 0.02 to 0.50%, Cu: less than 0.1%, Nb: 0.005 to 0.50%, Ti: 0.05 to 0.50%, and N: 0.001 to 0.030%, the balance being Fe and inevitable impurities, the ferritic stainless steel satisfying the following equations (1) and (2):
0.6≦Si+Al+Ti≦1.8  (1)

Nb+1.3Ti+0.9V+0.2Al>0.55  (2)

wherein the chemical symbols in the expressions represent the contents (mass %) of the respective elements; and
wherein the ferritic stainless steel sheet has a pitting potential of 0 mVolt or above.

2. The ferritic stainless steel according to claim 1 , further comprising, by mass %, one or more selected from Zr: not more than 1.0%, W: not more than 1.0%, REM: not more than 0.1%, Co: not more than 0.3% and B: not more than 0.1%.

3. The ferritic stainless steel according to claim 2 , wherein the ferritic stainless steel sheet has a reactivation rate of 0.01% or less.

4. The ferritic stainless steel according to claim 2 comprising, by mass %, Cr: 21.0 to 26.0%.

5. The ferritic stainless steel according to claim 4 , wherein the ferritic stainless steel sheet has a reactivation rate of 0.01% or less.

6. The ferritic stainless steel according to claim 1 comprising, by mass %, Cr: 21.0 to 26.0%.

7. The ferritic stainless steel according to claim 6 , wherein the ferritic stainless steel sheet has a reactivation rate of 0.01% or less.

8. The ferritic stainless steel according to claim 1 , wherein the ferritic stainless steel sheet has a reactivation rate of 0.01% or less.

Assignees

• Jfe Steel Corp

Inventors

• Ishii Tomohiro
• Ishikawa Shin
• Ogata Hiroyuki

Classifications

• C22C38/04

  containing manganese · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C22C38/46

  with vanadium · CPC title

• C22C38/004

  Very low carbon steels, i.e. having a carbon content of less than 0,01% · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title