IP Library Granted Patent US 11,725,266
Granted Patent B2
US 11,725,266 · App. 16/668,997 · Granted Aug 15, 2023

Stainless steel alloys, turbocharger components formed from the stainless steel alloys, and methods for manufacturing the same

Inventors: Pavan Chintalapati (Bangalore, IN); Philippe Renaud (Sanchey, FR); Piotr Gawron (Cracow, PL); Bjoern Schenk (Commugny, CH)
Assignee: Garrett Transportation I Inc.
C22C38/58C22C38/001C22C38/02C22C38/48F01D25/005
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Quick Facts
Patent No.
US 11,725,266
App. No.
16/668,997
Granted
Aug 15, 2023
Kind
B2
Abstract

Disclosed is an austenitic stainless steel alloy that includes or consists of, by weight, about 20.0% to about 21.5% chromium, about 8.5% to about 10.0% nickel, about 4.0% to about 5.0% manganese, about 0.5 to about 1.5% niobium, about 0.5% to about 2.0% silicon, about 0.4% to about 0.5% carbon, about 0.2% to about 0.3% nitrogen, and a balance of iron with inevitable/unavoidable impurities. The elements tungsten and molybdenum are excluded beyond impurity levels. Turbocharger turbine housings made of the stainless steel alloy, and methods of making the same, are also disclosed. The stainless steel alloy is suitable for use in turbocharger turbine applications for temperatures up to about 1020° C.

Claims (68)

1. An austenitic stainless steel alloy, comprising, by weight:

20.0% to 21.5% chromium;

8.5% to 10.0% nickel;

4.0% to 5.0% manganese;

0.5 to 1.5% niobium;

0.5% to 1.0% silicon;

0.4% to 0.5% carbon;

0.24% to 0.3% nitrogen; and

a balance of iron with inevitable/unavoidable impurities,

wherein molybdenum, and tungsten are excluded from the alloy beyond impurity levels, and wherein the austenitic stainless steel alloy maintains a stable austenite phase up to a temperature above 1020° C. without a delta ferrite phase being substantially present, wherein the austenitic stainless steel alloy is in a form of a cast product and includes eutectic carbides of Nb, and wherein no delta ferrite phase is present or formed at any temperature above 1020° C. up to 1600° C.

2. The austenitic stainless steel alloy of claim 1 comprising 20.3% to 21.2% chromium.

3. The austenitic stainless steel alloy of claim 1 comprising 8.8% to 9.7% nickel.

4. The austenitic stainless steel alloy of claim 1 comprising 4.6% to 4.9% manganese.

5. The austenitic stainless steel alloy of claim 1 comprising 0.6% to 0.9% silicon.

6. The austenitic stainless steel alloy of claim 1 comprising 0.42% to 0.48% carbon.

7. The austenitic stainless steel alloy of claim 1 , consisting of, by weight:

20.0% to 21.5% chromium;

8.5% to 10.0% nickel;

4.0% to 5.0% manganese;

0.5 to 1.5% niobium;

0.5% to 1.0% silicon;

0.4% to 0.5% carbon;

0.24% to 0.3% nitrogen; and

a balance of iron with inevitable/unavoidable impurities.

8. The austenitic stainless steel alloy of claim 1 , wherein aluminum is excluded from the alloy.

9. A turbocharger turbine component comprising:

an austenitic stainless steel alloy, wherein the austenitic stainless steel alloy comprises, by weight:

20.0% to 21.5% chromium;

8.5% to 10.0% nickel;

4.0% to 5.0% manganese;

0.5 to 1.5% niobium;

0.5% to 1.0% silicon;

0.4% to 0.5% carbon;

0.24% to 0.3% nitrogen; and

a balance of iron with inevitable/unavoidable impurities,

wherein molybdenum, and tungsten are excluded from the alloy beyond impurity levels, and wherein the austenitic stainless steel alloy maintains a stable austenite phase up to a temperature above 1020° C. without a delta ferrite phase being substantially present, wherein the austenitic stainless steel alloy is in a form of a cast product and includes eutectic carbides of Nb, and wherein no delta ferrite phase is present or formed at any temperature above 1020° C. up to 1600° C.

10. The turbocharger turbine component of claim 9 ,

wherein the austenitic stainless steel comprises about 20.3% to about 21.2% chromium.

11. The turbocharger turbine component of claim 9 ,

wherein the austenitic stainless steel alloy comprises about 8.8% to about 9.7% nickel.

12. The turbocharger turbine component of claim 9 ,

wherein the austenitic stainless steel alloy comprises about 4.6% to about 4.9% manganese.

13. The turbocharger turbine component of claim 9 ,

wherein the austenitic stainless steel alloy comprises about 0.6% to about 0.9% silicon.

14. The turbocharger turbine component of claim 9 ,

wherein the austenitic stainless steel alloy comprises about 0.42% to about 0.48% carbon.

15. The turbocharger turbine component of claim 9 ,

wherein the austenitic stainless steel alloy consists of, by weight:

20.0% to 21.5% chromium;

8.5% to 10.0% nickel;

4.0% to 5.0% manganese;

0.5 to 1.5% niobium;

0.5% to 1.0% silicon;

0.4% to 0.5% carbon;

0.24% to 0.3% nitrogen; and

a balance of iron with inevitable/unavoidable impurities.

16. The turbocharger turbine component of claim 9 , wherein the turbocharger turbine component comprises a turbocharger turbine housing.

17. A vehicle comprising the turbocharger turbine component of claim 9 .

18. A method of making a turbocharger turbine component comprising forming the turbocharger turbine component using an austenitic stainless steel alloy, wherein the austenitic stainless steel alloy comprises, by weight:

20.0% to 21.5% chromium;

8.5% to 10.0% nickel;

4.0% to 5.0% manganese;

0.5 to 1.5% niobium;

0.5% to 1.0% silicon;

0.4% to 0.5% carbon;

0.24% to 0.3% nitrogen; and

a balance of iron with inevitable/unavoidable impurities,

wherein molybdenum, and tungsten are excluded from the alloy beyond impurity levels, and wherein the austenitic stainless steel alloy maintains a stable austenite phase up to a temperature above 1020° C. without a delta ferrite phase being substantially present, wherein the austenitic stainless steel alloy is in a form of a cast product and includes eutectic carbides of Nb, and wherein no delta ferrite phase is present or formed at any temperature above 1020° C. up to 1600° C.

Assignments (3)
CORRECTIVE ASSIGNMENT TO CORRECT THE THE TYPOS IN THE APPLICATION NUMBER PREVIOUSLY RECORDED AT REEL: 056111 FRAME: 0583. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Feb 25, 2022
From: GARRETT TRANSPORTATION I INC.
To: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
Reel/Frame 059250/0792 →
SECURITY AGREEMENT Recorded May 3, 2021
From: GARRETT TRANSPORTATION I INC.
To: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
Reel/Frame 056111/0583 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 30, 2019
From: CHINTALAPATI, PAVAN; RENAUD, PHILIPPE; GAWRON, PIOTR; SCHENK, BJOERN
To: GARRETT TRANSPORTATION I INC.
Reel/Frame 050868/0157 →