Ferritic stainless steel material for brazing and heat exchanger member

Patent metadata

Field	Value
Publication number	US-9932650-B2
Application number	US-201013376708-A
Country	US
Kind code	B2
Filing date	Jun 14, 2010
Priority date	Jun 15, 2009
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A ferritic stainless steel material for brazing without grain coarsening has a partially recrystallized structure and composition comprising, in % by mass, C:0.03% or less, Si: more than 0.1 to 3%, Mn: 0.1 to 2%, Cr: 10 to 35%, Nb: 0.2 to 0.8%, N: 0.03% or less, if necessary, at least one of Mo, Cu, V and W: 4% or less in total, at least one of Ti and Zr: 0.5% or less in total, at least one of Ni and Co: 5% or less in total, or at least one of Al: 6% or less, REM (rare earth metal): 0.2% or less and Ca: 0.1% or less, the remainder being Fe and unavoidable impurities, wherein area ratio in percentage of recrystallized grains formed by heating after cold working is from 10 to 80%.

First claim

The invention claimed is:

1. A ferritic stainless steel material for brazing, having partially recrystallized structure and a chemical composition consisting of, in % by mass, C: 0.03% or less, Si: more than 0.1 to 3%, Mn: 0.1 to 2%, Cr: 10 to 35%, Nb: 0.2 to 0.8%, N: 0.03% or less, and the remainder being Fe and unavoidable impurities, wherein area ratio in percent of recrystallized grains formed by heating after cold working is from 10 to 80%.

2. A ferritic stainless steel material for brazing, having partially recrystallized structure and a chemical composition consisting of, in % by mass, C: 0.03% or less, Si: more than 0.1 to 3%, Mn: 0.1 to 2%, Cr: 10 to 35%, Nb: 0.2 to 0.8%, N: 0.03% or less, at least one of Mo, Cu, V and W in the total amount of 4% or less, and the remainder being Fe and unavoidable impurities, wherein area ratio in percent of recrystallized grains formed by heating after cold working is from 10 to 80%.

3. A ferritic stainless steel material for brazing, having partially recrystallized structure and a chemical composition consisting of, in % by mass, C: 0.03% or less, Si: more than 0.1 to 3%, Mn: 0.1 to 2%, Cr: 10 to 35%, Nb: 0.2 to 0.8%, N: 0.03% or less, at least one of Mo. Cu, V and W in the total amount of 4% or less, at least one of Ti and Zr in the total amount of 0.5% or less, and the remainder being Fe and unavoidable impurities, wherein area ratio in percent of recrystallized grains formed by heating after cold working is from 10 to 80%.

4. A ferritic stainless steel material for brazing, having partially recrystallized structure and a chemical composition consisting of, in % by mass, C: 0.03% or less, Si: more than 01 to 3%, Mn: 0.1 to 2%. Cr: 10 to 35%, Nb: 0.2 to 0.8%, N: 0.03% or less, at least one of Mo, Cu, V and W in the total amount of 4% or less, at least one of Ti and Zr in the total amount of 0.5% or less, at least one of Ni and Co in the total amount of 5% or less, and the remainder being Fe and unavoidable impurities, wherein area ratio in percent of recrystallized grains formed by heating after cold working is from 10 to 80%.

5. A ferritic stainless steel material for brazing, having partially recrystallized structure and a chemical composition consisting of, in % by mass, C: 0.03% or less, Si: more than 0.1 to 3%, Mn: 0.1 to 2%, Cr: 10 to 35%, Nb: 0.2 to 0.8% N: 0.03% or less, at least one of Mo, Cu, V and W in the total amount of 4% or less, at least one of Ti and Zr in the total amount of 0.5% or less, at least one of Ni and Co in the total amount of 5% or less, Al: 0.06to 6%, and the remainder being Fe and unavoidable impurities, wherein area ratio in percent of recrystallized grains formed by beating after cold working is from 10 to 80%.

6. A ferritic stainless steel material for brazing, having partially recrystallized structure and a chemical composition consisting of, in % by mass, C: 0.03% or less, Si: more than 0.1 to 3%, Mn: 0.1 to 2%, Cr: 10 to 35%, Nb: 0.2 to 0.8%, N: 0.03% or less, at least one of Mo, Cu V and W in the total amount of 4% or less, Al: 0.06 to 6%, and the remainder being Fe and unavoidable impurities, wherein area ratio in percent of recrystallized grains formed by heating after cold working is from 10 to 80%.

7. The ferritic stainless steel material according to any one of claims 1 - 5 and 6 , wherein the total content of C and N is 0.01% or more.

8. A heat exchanger member comprising the ferritic stainless steel material according to any one of claims 1 to 5 and 6 , brazed using any one of nickel brazing filler defined in Japanese Industrial Standards Z3265, nickel brazing filler containing Ni in an amount of 35% by mass or more, copper brazing filler or copper alloy brazing filler, defined in Japanese Industrial Standards Z3262, and iron brazing filler, wherein the steel has ferrite grains with a thickness less than a thickness of the steel and has an average crystal grain size of 500 μm or less.

9. The heat exchanger member according to claim 8 , which is an exhaust gas recirculation cooler of automobiles, obtained by brazing the steel material using nickel brazing filler defined in Japanese Industrial Standards Z3265 or nickel brazing filler containing Ni in an amount of 35% by mass or more.

Assignees

• Oku Manabu
• Nakamura Sadayuki
• Hori Yoshiaki
• Nisshin Steel Co Ltd

Inventors

• Oku Manabu
• Nakamura Sadayuki
• Hori Yoshiaki

Classifications

• C21D6/002

  containing Cr (C21D6/004 takes precedence) · CPC title

• C22C38/20

  with copper · CPC title

• C22C38/001

  containing N · CPC title

• F28F21/089

  Coatings, claddings or bonding layers made from metals or metal alloys (F28F19/06 takes precedence) · CPC title

• B23K35/308

  with Cr as next major constituent · CPC title