FERRITIC STAINLESS STEEL SHEET FOR EGR COOLERS

• US 20110176953A1
• Filed: 10/23/2009
• Published: 07/21/2011
• Est. Priority Date: 10/24/2008
• Status: Abandoned Application

• Current Assignee: Nippon Steel & Sumikin Stainless Steel Corporation (Nippon Steel Corporation)
• Original Assignee: Nippon Steel & Sumikin Stainless Steel Corporation (Nippon Steel Corporation)
• Inventors: Hiraide, Nobuhiko, Maeda, Shigeru, Takahashi, Akihiko
• Application Number:
  US12/998,242
• Publication Number:
  US 20110176953A1
• Time in Patent Office: Days
• US Class Current: 420/41
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/20 with copper
• CPC Class Codes: C22C 38/26 with niobium or tantalum
• CPC Class Codes: F02M 26/11 Manufacture or assembly of EGR systems; Materials or coatings specially adapted for EGR systems
• CPC Class Codes: F02M 26/29 Constructional details of the coolers, e.g. pipes, plates, ribs, insulation or materials
• CPC Class Codes: F02M 26/50 Arrangements or methods for preventing or reducing deposits, corrosion or wear caused by impurities arrangement or layout of EGR passages with means for cleaning or treating the recirculated gases F02M26/35; protection of EGR valves from damage F02M26/74
• CPC Class Codes: F28F 19/06 of metal
• CPC Class Codes: F28F 21/083 from stainless steel
• CPC Class Codes: F28F 21/089 Coatings, claddings or bonding layers made from metals or metal alloys F28F19/06 takes precedence

Abstract

A ferritic stainless steel sheet for EGR coolers includes at least, by mass % C: 0.03% or less, N: 0.05% or less, Si: 0.1% to 1%, Mn: 0.02% to 2%, Cu: 0.2% to 1.5%, Cr: 15% to 25%, Nb: 8 (C+N) % to 1%, Al: 0.5% or less, and Fe and inevitable impurities as the balance, wherein the steel sheet further includes, by mass %, Ti at an amount fulfilling the following formulae (1) and (2), and Cr and Cu are included at amounts fulfilling the following formula (3),

Ti-3N≦0.03  (1),

10(Ti-3N)+Al≦0.5  (2),

and

Cr+2.3Cu≧18  (3).

Claims

1. A ferritic stainless steel sheet for EGR coolers, comprising:

at least, by mass %,

C;

0.03% or less;

N;

0.05% or less;

Si;

0.1% to 1%;

Mn;

0.02% to 2%;

Cu;

0.2% to 1.5%;

Cr;

15% to 25%;

Nb;

8(C+N) % to 1%;

Al;

0.5% or less; and

Fe and inevitable impurities as the balance,

wherein the steel sheet further comprises, by mass %, Ti at an amount fulfilling the following formulae (1) and (2), and

Cr and Cu are included at amounts fulfilling the following formula (3),

Ti-3N≦

0.03 

 

(1)

10(Ti-3N)+Al≦

0.5 

 

(2)

Cr+2.3Cu≧

18 

 

(3).

2. The ferritic stainless steel sheet for EGR coolers according to claim 1,

wherein the steel sheet further comprises, by mass %, either one or both of Mo:

3% or less, and Ni;

3% or less at amounts fulfilling the following formula (4),

Cr+1.9Mo+1.6Ni+2.3Cu≧

18 

 

(4).

3. The ferritic stainless steel sheet for EGR coolers according to claim 1,

wherein the steel sheet further comprises, by mass %, either one or both of V:

3% or less, and W;

5% or less.

4. The ferritic stainless steel sheet for EGR coolers according to claim 1,

wherein the steel sheet further comprises, by mass %, one or more selected from the group consisting of Ca:

0.002% or less, Mg;

0.002% or less, and B;

0.005% or less.

5. The ferritic stainless steel sheet for EGR coolers according to claim 1,

wherein the steel sheet fulfills C+N:

0.015% or more.