Stainless steel having excellent oxidation resistance at high temperature

Patent metadata

Field	Value
Publication number	US-10513765-B2
Application number	US-201615377785-A
Country	US
Kind code	B2
Filing date	Dec 13, 2016
Priority date	Oct 12, 2016
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

Disclosed herein is stainless steel having excellent tensile strength, fatigue strength, oxidation resistance at high temperature environment. According to an exemplary embodiment of the present invention, the stainless steel having excellent oxidation resistance at high temperature includes C: 0.01 to 0.2%, Si: 0.1 to 1.0%, Mn: 0.1 to 2.0%, Cr: 12.0 to 30.0%, V: 0.01 to 0.5%, Nb: 0.01 to 0.5%, Al: 0.1 to 4.0%, Co: 0.01 to 5.0%, Mo: 0.01 to 4.0%, W: 0.01 to 4.0%, B: 0.001 to 0.15%, Ni: 5.0 to 20.0% as wt %, the balance Fe, and other inevitable impurities.

First claim

What is claimed is:

1. An improved stainless steel, wherein the stainless steel consisting of:
between 0.01 and 0.2 weight % carbon;
between 0.01 and 0.1 weight % silicon;
between 0.1 and 2.0 weight % manganese;
between 12.0 and 30.0 weight % chromium;
between 0.01 and 0.5 weight % vanadium;
between 0.01 and 0.5 weight % niobium;
between 0.11 and 4.0 weight % aluminum;
between 0.01 and 5.0 weight % cobalt;
between 0.01 and 4.0 weight % molybdenum;
between 0.01 and 4.0 weight % tungsten;
between 0.001 and 0.15% boron; and
between 5.0 and 20.0% weight % nickel; and
wherein the remaining weight percent is comprised substantially of iron and a small amount of impurities.

2. The improved stainless steel of claim 1 , wherein the stainless steel forms niobium carbide, composite carbide and composite boride structures.

3. The improved stainless steel of claim 2 , wherein the composite carbide is (Cr,Mo)23C6.

4. The improved stainless steel of claim 2 , wherein the composite boride is (Cr,Fe)2B.

5. The improved stainless steel of claim 2 , wherein the structure of the stainless steel further includes at least one of (Mo,Cr,W)2B and (Mo,W)3B2 as the composite boride.

6. The improved stainless steel of claim 2 , wherein the particle size of the composite carbide is less than or equal to 50 nm.

7. The improved stainless steel of claim 1 , wherein the stainless steel has a tensile strength at temperatures above room temperature greater than or equal to 250 MPa.

8. The improved stainless steel of claim 1 , wherein the stainless steel has a fatigue strength greater than or equal to 95 MPa.

9. The improved stainless steel of claim 1 , wherein the stainless steel has an oxidation weighting less than or equal to 0.9 g/m 2 .

10. The improved stainless steel of claim 1 , wherein the stainless steel has a tensile strength at temperatures above room temperature greater than or equal to 250 MPa; a fatigue strength greater than or equal to 95 MPa; and an oxidation weighting less than or equal to 0.9 g/m 2 .

11. The stainless steel of claim 1 , wherein the stainless steel has a room-temperature tensile strength greater than or equal to 710 MPa and an A5 elongation according to ASTM A370 standard test greater than or equal to 50%.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Cha Sung Chul
• Kim Ik Soo
• Kang Young Joon

Classifications

• C22C38/04

  containing manganese · CPC title

• C22C38/48

  with niobium or tantalum · CPC title

• C22C38/52

  with cobalt · CPC title

• C22C38/54

  with boron · CPC title

• C22C38/46 Primary

  with vanadium · CPC title