IP Library Granted Patent US 6,896,978
Granted Patent B2
US 6,896,978 · App. 10/083,355 · Granted May 24, 2005

Joint construction of cobalt-based alloy

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Quick Facts
Patent No.
US 6,896,978
App. No.
10/083,355
Granted
May 24, 2005
Kind
B2
Abstract

In the joint construction of cobalt-based alloy, a cobalt-based alloy layer 1 , in which granular or massive eutectic carbide 2 disperses, is joined to a metal of a base metal 37 via an insert metal layer 36 . For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100° C. for a retention time of 1 hour with an insert metal with a thickness of about 40 μm being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 μm in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layer 1 after bonding contains granular or massive eutectic carbide.

Claims (21)

1. A joint construction of cobalt-based alloy in which a cobalt-based alloy material portion is diffusion bonded to a base metal portion by interposing an insert metal between said cobalt-based alloy portion, in which granular or massive eutectic carbide disperses in a matrix of metal microstructure, and said base metal portion, wherein

a layer which has an element of said insert metal is formed over said base metal portion, and said cobalt-bases alloy portion is located over said layer.

2. The joint construction of cobalt-based alloy according to claim 1 , wherein said base metal portion and said cobalt-based alloy portion contain an element diffused from said insert metal.

3. The joint construction of cobalt-based alloy according to claim 2 , wherein said insert metal layer contains an element diffused from said base metal portion and cobalt diffused from said cobalt-based alloy portion.

4. The joint construction of cobalt-based alloy material according to claim 3 , wherein the grain size of said eutectic carbide is not larger than 30 μm.

5. The joint construction of cobalt-based alloy material according to claim 3 , wherein said base metal portion is a material selected from the group consisting of carbon steel, low alloy steel, and stainless steel.

6. The joint construction of cobalt-based alloy material according to claim 5 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Fe, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

7. The joint construction of cobalt-based alloy material according to claim 3 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Fe, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

8. The joint construction of cobalt-based alloy material according to claim 2 , wherein the grain size of said eutectic carbide is not larger than 30μm.

9. The joint construction of cobalt-based alloy material according to claim 2 , wherein said base metal portion is a material selected from the group consisting of carbon steel, low alloy steel, and stainless steel.

10. The joint construction of cobalt-based alloy material according to claim 2 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Fe, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

11. The joint construction of cobalt-based alloy according to claim 1 , wherein said insert metal layer contains an element diffused from said base metal portion and cobalt diffused from said cobalt-based alloy portion.

12. The joint construction of cobalt-based alloy material according to claim 11 , wherein the grain size of said eutectic carbide is not larger than 30 μm.

13. The joint construction of cobalt-based alloy material according to claim 11 , wherein said base metal portion is a material selected from the group consisting of carbon steel, low alloy steel, and stainless steel.

14. The joint construction of cobalt-based alloy material according to claim 13 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Fe, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

15. The joint construction of cobalt-based alloy material according to claim 13 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Fe, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

16. The joint construction of cobalt-based alloy material according to claim 1 , wherein the grain size of said eutectic carbide is not larger than 30 μm.

17. The joint construction of cobalt-based alloy material according to claim 16 , wherein said base metal portion is a material selected from the group consisting of carbon steel, low alloy steel, and stainless steel.

18. The joint construction of cobalt-based alloy material according to claim 16 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

19. The joint construction of cobalt-based alloy material according to claim 1 , wherein said base metal portion is a material selected from the group consisting of carbon steel, low alloy steel, and stainless steel.

20. The joint construction of cobalt-based alloy material according to claim 1 , wherein said cobalt-based alloy portion contains 0.6 to 3% C, 2% or less Si, 25 to 32% Cr, 15% or less W, 0 to 3% Fe, 0 to 3% Ni, and 0 to 6% Mo by weight, the balance being Co and unavoidable impurities.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 20, 2007
From: HITACHI, LTD.
To: HITACHI-GE NUCLEAR ENERGY, LTD.
Reel/Frame 019881/0466 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 17, 2002
From: KIYOTOKI, YOSHIHISA; CHIGASAKI, MITSUO; MATSUSHITA, SHIZUO; KUNIYA, JIRO; KATO, TAKAHIKO; CHIBA, YOSHITERU
To: HITACHI, LTD.
Reel/Frame 012910/0994 →