Method of manufacturing a ferrous alloy article using powder metallurgy processing

• US 10,094,007 B2
• Filed: 05/20/2014
• Issued: 10/09/2018
• Est. Priority Date: 10/24/2013
• Status: Active Grant

• Current Assignee: CRS Incorporated (Carpenter Technology Corporation)
• Original Assignee: CRS Incorporated (Carpenter Technology Corporation)
• Inventors: Wert, David E., Armstrong, Timothy R., Helmick, David A., Schmidt, Michael L.
• Primary Examiner(s): KLEMANSKI, HELENE G
• Application Number:
  US14/282,762
• Publication Number:
  US 20150118095A1
• Time in Patent Office: 1,603 Days
• Field of Search: 420 36, 420 38, 420 39
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/15 Hot isostatic pressing
• CPC Class Codes: B22F 3/17 by forging
• CPC Class Codes: C21D 1/18 Hardening C21D1/02 takes precedence; Quenching with or without subsequent tempering quenching devices C21D1/62
• CPC Class Codes: C21D 2211/004 Dispersions; Precipitations
• CPC Class Codes: C21D 2211/008 Martensite
• CPC Class Codes: C21D 6/004 containing Cr and Ni
• CPC Class Codes: C21D 6/04 Hardening by cooling below 0 degrees Celsius
• CPC Class Codes: C21D 7/13 by hot working
• CPC Class Codes: C21D 8/005 of ferrous alloys C21D8/02 - C21D8/12 take precedence
• CPC Class Codes: C22C 33/0285 with Cr, Co, or Ni having a minimum content higher than 5%
• CPC Class Codes: C22C 33/04 by melting
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/005 containing rare earths, i.e. Sc, Y, Lanthanides
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/42 with copper
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/46 with vanadium
• CPC Class Codes: C22C 38/48 : with niobium or tantalum
• CPC Class Codes: C22C 38/50 : with titanium or zirconium
• CPC Class Codes: C22C 38/52 : with cobalt

Abstract

A method of manufacturing a ferrous alloy article is disclosed and includes the steps of melting a ferrous alloy composition into a liquid, atomizing and solidifying of the liquid into powder particles, outgassing to remove oxygen from the surface of the powder particles, and consolidating the powder particles into a monolithic article.

Claims

1. A method of manufacturing a ferrous alloy article, comprising the steps of:

melting a ferrous alloy composition into a liquid, the ferrous alloy composition including, in wt. % of about C 0.2-0.45; and

of Co at least about 1 up to 6;

atomizing and solidifying the liquid into powder particles;

removing oxygen from surfaces of the powder particles through vacuum hot outgassing to remove oxides and reducing a bulk oxygen content to approximately ≤

20 ppm; and

consolidating the powder particles into a monolithic article.

2. The method of claim 1, wherein the step of consolidating the powder particles is performed using hot isostatic pressing (HIP).

3. The method of claim 2, wherein removal of oxygen from the surface performed through outgassing is performed on the powder particles positioned in a container.

4. The method of claim 1, wherein atomization is performed using a high pressure inert gas.

5. The method of claim 4, wherein the high pressure inert gas is Nitrogen.

6. The method of claim 4, wherein the high pressure inert gas is Argon.

7. The method of claim 1, wherein the monolithic article is consolidated from the powder particles in a container.

8. The method of claim 1, further comprising the step of separating the powder particles by size.

9. The method of claim 8, wherein the separated powder particles are mixed into a homogenized blend.

10. The method of claim 1, further comprising the step of screening the powder particles using a mesh.

11. The method of claim 10, wherein the separated powder particles are mixed into a homogenized blend.

12. The method of claim 11, wherein outgassing reduces a bulk oxygen content of a resulting consolidated product to approximately ≤

10 ppm.

13. The method of claim 1, further comprising the step of filing a container with the powder particles.

14. The method of claim 1, further comprising the step of forging the monolithic article.

15. The method of claim 1, further comprising the step of hot working the monolithic article.

16. The method of claim 1, wherein the ferrous alloy composition includes, in wt. % of, about:

17. The method of claim 16, wherein the ferrous alloy composition includes, in wt. % of, about:

18. A method of manufacturing a ferrous alloy article, comprising the steps of:

melting a ferrous alloy composition into a liquid, the ferrous alloy composition including, in wt. % of about C 0.2-0.45; and

of Co at least about 1 up to 6;

atomizing and solidifying the liquid into powder particles;

separating the powder particles by size;

mixing the powder particles into a homogenized blend;

removing oxygen from surfaces of the powder particles through vacuum hot outgassing to remove oxides and reducing a bulk oxygen content to approximately ≤

20 ppm; and

consolidating the powder particles into a monolithic article.

19. The method of claim 18, wherein a high pressure inert gas selected from the group consisting of nitrogen and argon is used in atomizing the liquid.

20. The method of claim 19, wherein outgassing reduces a bulk oxygen content of a resulting consolidated product to approximately ≤

10 ppm.

21. The method of claim 20, further comprising the step of filing a container with the powder particles.

22. The method of claim 21, further comprising the step of forging the monolithic article.

23. The method of claim 22, further comprising the step of hot working the monolithic article.

24. A method of manufacturing a ferrous alloy article, comprising the steps of:

melting a ferrous alloy composition into a liquid, the ferrous alloy composition including, in wt. % of about C 0.2-0.45; and

of Co at least about 1 up to 6;

atomizing and solidifying the liquid into powder particles using a high pressure inert gas selected from the group consisting of nitrogen and argon;

separating the powder particles by size;

mixing the separated powder particles into a homogenized blend;

vacuum hot outgassing to remove oxides from surfaces of the powder particles positioned in a container to reduce a bulk oxygen content to approximately ≤

20 ppm; and

consolidating the powder particles into a monolithic article using hot isostatic pressing (HIP).

25. The method of claim 24, wherein outgassing reduces a bulk oxygen content of a resulting consolidated product to approximately ≤

10 ppm.

26. The method of claim 24, further comprising the step of forging the monolithic article.

27. The method of claim 26, further comprising the step of hot working the monolithic article.