Cr—Fe—Ni-based alloy product

Patent metadata

Field	Value
Publication number	US-11466347-B2
Application number	US-201816970211-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Feb 20, 2018
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

The purpose of the present invention is to provide an alloy product which has both of high corrosion resistance enough to withstand severe corrosive/high-temperature environments and mechanical properties equivalent to or better than those of stainless steel, and which can be produced at lower cost than a Ni-based alloy. The Cr—Fe—Ni-based alloy product of the present invention is a product produced using a Cr—Fe—Ni-based alloy containing Cr as a largest-content component, wherein the product has such a microstructure that a dual-phase structure having a ferrite phase and an austenite phase coexisting therein serves as a matrix phase and an L12-type Ni-based intermetallic compound phase is dispersed and precipitated in the austenite phase.

First claim

The invention claimed is:

1. A Cr—Fe—Ni-based alloy product which is a product produced using a Cr—Fe—Ni-based alloy containing Cr as a largest-content component, the chemical composition of the Cr—Fe—Ni-based alloy consisting of:
44 to 75% by mass inclusive of Cr,
10 to 33% by mass inclusive of Fe,
10 to 40% by mass inclusive of Ni,
0.05 to 2% by mass inclusive of Mn,
0.05 to 1% by mass inclusive of Si,
0.5 to 5% by mass inclusive of Al,
more than 0% by mass and 0.1% by mass or less of C,
more than 0% by mass and 2% by mass or less of N,
more than 0% by mass and 0.2% by mass or less of O,
more than 0% by mass and 0.04% by mass or less of P,
more than 0% by mass and 0.01% by mass or less of S, and
as an optional auxiliary component: at least one of Ti in an amount of more than 0% by mass and 4% by mass or less and Cu in an amount of more than 0% by mass and 2% by mass or less,
wherein the product has such a microstructure that a dual-phase structure having a ferrite phase and an austenite phase coexisting therein serves as a matrix phase and an L1 2 -type Ni-based intermetallic compound phase is dispersed and precipitated in the austenite phase, and
wherein the occupancy of the ferrite phase in the microstructure in the product is 60% by area or more.

2. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein the Ni-based intermetallic compound phase comprises an Ni 3 Al phase and/or an Ni 3 (Al,Ti) phase.

3. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein the product is a cast molded body having a cast structure.

4. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein the product is a recrystallized molded body having a recrystallized structure.

5. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein the product is a rapidly solidified body having a rapidly solidified structure.

6. The Cr—Fe—Ni-based alloy product according to claim 5 ,
wherein the rapidly solidified body is a composite body in which a coating layer composed of a Cr—Fe—Ni-based alloy having the rapidly solidified structure is formed on a base.

7. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein the product is a powder metallurgically molded body having a sintered structure.

8. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein:
the room-temperature Vickers hardness is 650 Hv or more;
the high-temperature Vickers hardness at 800° C. is 320 Hv or more; and
the tensile strength at 700° C. is 650 MPa or more when a high-temperature tensile test is carried out in accordance with JIS G 0567.

9. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein the product is a powder having a rapidly solidified structure.

10. The Cr—Fe—Ni-based alloy product according to claim 1 , wherein the average mass loss rate is less than 0.1 g/(m 2 ·h) when a sulfuric acid corrosion test is carried out in accordance with JIS G 0591.

11. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein content of the Fe is from 15.5% by mass to 33% by mass.

12. The Cr—Fe—Ni-based alloy product according to claim 1 ,
wherein content of the Cr is from 47.6% by mass to 75% by mass.

Assignees

• Hitachi Ltd

Inventors

• Noujima Masafumi

Classifications

• C22C27/06 Primary

  Alloys based on chromium · CPC title

• C22F1/11

  of chromium or alloys based thereon · CPC title

• C23C4/06

  Metallic material · CPC title

• B23K28/00

  Welding or cutting not covered by groups B23K5/00 - B23K26/00 · CPC title

• C22C30/00

  Alloys containing less than 50% by weight of each constituent · CPC title