Iron based alloy suitable for providing a hard and corrosion resistant coating on a substrate, article having a hard and corrosion resistant coating, and method for its manufacture

Patent metadata

Field	Value
Publication number	US-11326239-B2
Application number	US-201716622444-A
Country	US
Kind code	B2
Filing date	Jun 21, 2017
Priority date	Jun 21, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

An iron-based alloy that is able to provide a coating on a substrate, the coating having simultaneously high hardness, corrosion resistance and bonding strength to the substrate. The iron-based alloy has 16.00-20.00% by weight Cr; 0.20-2.00% by weight B; 0.20-4.00% by weight Ni; 0.10-0.35% by weight C; 0.10-4.00% by weight Mo; optionally 1.50% by weight or less Si; optionally 1.00% by weight or less Mn, optionally 3.90% by weight or less Nb; optionally 3.90% by weight or less V; optionally 3.90% by weight or less W; and optionally 3.90% by weight or less Ti; the balance being Fe and unavoidable impurities; with the proviso that the total amount of Mo, Nb, V, W and Ti is in the range of 0.1-4.0% by weight of the alloy.

First claim

The invention claimed is:

1. An iron-based alloy, consisting of
16.00-20.00% by weight Cr;
0.20-2.00% by weight B;
0.20-4.00% by weight Ni;
0.10-0.35% by weight C;
0.10-4.00% by weight Mo;
optionally 1.50% by weight or less Si;
optionally 1.00% by weight or less Mn,
optionally 3.90% by weight or less Nb;
optionally 3.90% by weight or less V;
optionally 3.90% by weight or less W; and
optionally 3.90% by weight or less Ti;
the balance being Fe and 0.10% by weight or less of unavoidable impurities;
provided that the total of Mo, Nb, V, W and Ti is in the range of 0.1-4.0% by weight of the alloy,

wherein the alloy is configured to provide a coating, where the coating has a hardness of 56 HRC or greater as measured by SS-EN ISO 6508-1:2016.

2. The iron-based alloy according to claim 1 , wherein the content of Cr is from 16.50-19.50% by weight.

3. The iron-based alloy according to claim 1 , wherein the content of B is from 0.20-1.20% by weight.

4. The iron-based alloy according to claim 1 , wherein the content of Ni is from 0.20-3.00% by weight.

5. The iron-based alloy according to claim 1 , wherein the content of Nb is from 0.20-3.00% by weight.

6. The iron-based alloy according to claim 1 , wherein the content of the optional components Nb, V, W and Ti is each 1.50% by weight or less.

7. The iron-based alloy according to claim 1 , which is in powder form.

8. The iron-based alloy according to claim 7 , wherein the powder contains no or less than 2% by weight of particles having a particle size exceeding 250 μm as measured by sieve analysis according to ASTM B214-16.

9. The iron-based alloy in powder form according to claim 7 , which consists of particles having a particle size between 5-200 μm as measured by sieve analysis according to ASTM B214-16.

10. A method for forming an coated article, comprising the steps of
providing a substrate and
forming a coating on the substrate

wherein the step of forming the coating utilizes an alloy powder as defined in claim 7 .

11. The method for forming a coated article according to claim 10 , wherein the step of forming a coating is a laser cladding step, a plasma spraying step, a plasma transfer arc step High Velocity Air-Fuel coating spraying, cold spraying or a High Velocity Oxy-fuel coating spraying step.

12. The method for forming a coated article according to claim 10 , wherein the article is a hydraulic cylinder or roller used in the mining or steel industry.

13. The iron-based alloy in powder form according to claim 7 , which consists of particles having a particle size between 20-200 μm as measured by sieve analysis according to ASTM B214-16.

14. An article having a substrate and a coating, the coating being formed from an iron-based alloy as defined in claim 1 .

15. Article according to claim 14 , which is a hydraulic cylinder or roller used in the mining or steel industry.

16. The article according to claim 14 , wherein the coating has one or both of
a hardness of 56 HRC or greater as measured by SS-EN ISO 6508-1:2016; and
a corrosion resistance of 5000 hours (30 weeks) or more in a neutral salt spray test (5% NaCl) at 35° C. according to ISO 9227:2017.

17. The article according to claim 14 , wherein the coating is metallurgically bond to the substrate.

18. The article according to claim 14 , wherein the substrate is made of a metal or metal alloy.

19. The article according to claim 14 , wherein the coating is formed by laser cladding, plasma spraying, High Velocity Oxy-fuel or High Velocity Air-Fuel coating spraying, cold spraying or plasma transfer arc of the iron-based alloy.

20. A method comprising forming a coating on a substrate with the iron-based alloy according to claim 1 .

Assignees

• Hoeganaes Ab Publ
• Hoeganaes Germany Gmbh

Inventors

• Cao Cecilia
• Zhu Chris
• Zhang Bruc
• Liu Crystal
• HALLéN HANS

Classifications

• B22F1/00

  Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties · CPC title

• C23C24/106

  Coating with metal alloys or metal elements only · CPC title

• C23C4/08

  containing only metal elements (C23C4/073 takes precedence) · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• C22C38/50

  with titanium or zirconium · CPC title