Low-cost, high-strength Fe—Ni—Cr alloys for high temperature exhaust valve applications

• US 9,752,468 B2
• Filed: 09/26/2014
• Issued: 09/05/2017
• Est. Priority Date: 06/18/2014
• Status: Active Grant

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Muralidharan, Govindarajan
• Primary Examiner(s): Zhu, Weiping
• Application Number:
  US14/497,550
• Publication Number:
  US 20160090878A1
• Time in Patent Office: 1,075 Days
• Field of Search: 1231883
• CPC Class Codes: C22C 19/056 with the maximum Cr content being at least 10% but less than 20%
• CPC Class Codes: C22C 30/00 Alloys containing less than 50% by weight of each constituent
• CPC Class Codes: C22C 30/02 containing copper
• CPC Class Codes: F01L 3/02 Selecting particular materials for valve-members or valve-seats; Valve-members or valve-seats composed of two or more materials

Abstract

An Fe—Ni—Cr alloy is composed essentially of, in terms of wt. %: 2.4 to 3.7 Al, up to 1.05 Co, 14.8 to 15.9 Cr, 25 to 36 Fe, up to 1.2 Hf, up to 4 Mn, up to 0.6 Mo, up to 2.2 Nb, up to 1.05 Ta, 1.9 to 3.6 Ti, up to 0.08 W, up to 0.03 Zr, 0.18 to 0.27 C, up to 0.0015 N, balance Ni, wherein, in terms of atomic percent: 8.5≦Al Ti Zr Hf Ta≦11.5, 0.53≦Al÷(Al Ti Zr Hf Ta)≦0.65, and 0.16≦Cr÷(Fe Ni Cr Mn)≦0.21, the alloy being essentially free of Cu, Si, and V.

Claims

1. An Fe—

Ni—

Cr alloy consisting essentially of, in terms of wt. %;

Al 2.4 to 3.7

Co up to 1.05

Cr 14.8 to 15.9

Fe 25 to 36

Hf up to 1.2

Mn up to 4

Mo up to 0.6

Nb up to 2.2

Ta up to 1.05

Ti 1.9 to 3.6

W up to 0.08

Zr up to 0.03

C 0.18 to 0.27

N up to 0.0015

balance Ni,

wherein, in terms of atomic percent;

8.5≦

Al Ti Zr Hf Ta≦

11.5,

0.53≦

Al÷

(Al Ti Zr Hf Ta)≦

0.65, and

0.16≦

Cr÷

(Fe Ni Cr Mn)≦

0.21,

said alloy being essentially free of Cu, Si, and V.

2. An Alloy in accordance with claim 1 wherein the range of Al is 2.5 to 3.56 weight percent.

3. An Alloy in accordance with claim 1 wherein the range of Co is up to 1.01 weight percent.

4. An Alloy in accordance with claim 1 wherein the range of Cr is 14.93 to 15.76 weight percent.

5. An Alloy in accordance with claim 1 wherein the range of Fe is 25.87 to 35 weight percent.

6. An Alloy in accordance with claim 1 wherein the range of Hf is up to 1 weight percent.

7. An Alloy in accordance with claim 1 wherein the range of Mn is up to 3.38 weight percent.

8. An Alloy in accordance with claim 1 wherein the range of Mo is up to 0.52 weight percent.

9. An Alloy in accordance with claim 1 wherein the range of Nb is up to 2 weight percent.

10. An Alloy in accordance with claim 1 wherein the range of Ta is up to 1.02 weight percent.

11. An Alloy in accordance with claim 1 wherein the range of Ti is 2 to 3.49 weight percent.

12. An Alloy in accordance with claim 1 wherein the range of W is up to 0.06 weight percent.

13. An Alloy in accordance with claim 1 wherein the range of Zr is up to 0.02 weight percent.

14. An Alloy in accordance with claim 1 wherein the range of C is 0.18 to 0.24 weight percent.

15. An Alloy in accordance with claim 1 wherein, in terms of atomic percent, 8.7≦

Al Ti Zr Hf Ta≦

11.48.

16. An Alloy in accordance with claim 15 wherein, in terms of atomic percent, 9≦

Al Ti Zr Hf Ta≦

11.45.

17. An Alloy in accordance with claim 1 wherein, in terms of atomic percent, 0.54≦

Al÷

(Al Ti Zr Hf Ta)≦

0.64.

18. An Alloy in accordance with claim 17 wherein, in terms of atomic percent, 0.55≦

Al÷

(Al Ti Zr Hf Ta)≦

0.63.

19. An Alloy in accordance with claim 1 wherein, in terms of atomic percent, 0.17≦

Cr÷

(Ni Fe Cr Mn)≦

0.20.

20. An Alloy in accordance with claim 19 wherein, in terms of atomic percent, 0.18≦

Cr÷

(Ni Fe Cr Mn)≦

0.19.