Wear-resistant iron-based alloy compositions comprising chromium

Patent metadata

Field	Value
Publication number	US-2021197524-A1
Application number	US-201917257041-A
Country	US
Kind code	A1
Filing date	Jun 25, 2019
Priority date	Jul 2, 2018
Publication date	Jul 1, 2021
Grant date	—

Abstract

An iron-based alloy composition including: boron (B): 1. 6-2.4 wt. %; carbon (C): 2.2-3.0 wt. %; chromium (Cr): 3.5-5.0 wt. %; manganese (Mn): below 0.8 wt. %; molybdenum (Mo): 16.0-19.5 wt. %; nickel (Ni): 1.0-2.0 wt. %; silicon (Si): 0.2-2.0 wt. %; vanadium (V): 10.8-13.2 wt. %; and balanced with iron (Fe). Further, an item including a substrate portion and a hardfacing coating bonded to the substrate portion, wherein the hardfacing coating is made by an overlay welding process using the iron-based alloy composition.

First claim

1 . An iron-based alloy composition comprising
boron (B): 1.6-2.4 wt. %; carbon (C): 2.2-3.0 wt. %; chromium (Cr): 3.5-5.0 wt. %; manganese (Mn): below 0.8 wt. %; molybdenum (Mo): 16.0-19.5 wt. %; nickel (Ni): 1.0-2.0 wt. %; silicon (Si): 0.2-2.0 wt. %; vanadium (V): 10.8-13.2 wt. %; and balanced with iron (Fe).

2 . The iron-based alloy composition according to claim 1 , wherein the amount of silicon is 0.2-1.5 wt. %.

3 . The iron-based alloy composition according to claim 1 , wherein the amount of boron is 1.8-2.3 wt. %.

4 . The iron-based alloy composition according to claim 1 , wherein the amount of chromium is 3.5-4.5 wt. %.

5 . The iron-based alloy composition according to claim 1 , wherein a total amount of impurities in the iron-based alloy composition is below 1 wt. %.

6 . The iron-based alloy composition according to claim 1 , wherein the alloy composition is a powder composition.

7 . The iron-based alloy composition according to claim 6 , wherein at least 95 wt. % of the powder composition has a particle size of up to 300 μm, and/or wherein at least 95 wt. % of the powder composition has a particle size of at least 5 μm.

8 . An item comprising a substrate portion and a coating bonded to the substrate portion, wherein the coating is made using an iron-based alloy composition according to claim 1 as a coating material.

9 . The item according to claim 8 , wherein the coating is applied by an overlay welding process.

10 . The item according to claim 8 , wherein dilution from the substrate material is below 20%.

11 . The item according to claim 8 , wherein the coating has a Rockwell hardness HRC of at least 60.

12 . The item according to claim 8 , wherein the coating has an abrasive wear resistance as determined according to ASTM G65, procedure A, of, below 15 mm 3 .

13 . The item according to claim 8 , wherein the coating has an impact wear as determined according to the ball impact wear testing method of more than 5 strikes for an impact energy per strike of 15 J, more than 15 strikes for an impact energy per strike of 10 J.

14 . The item according to claim 8 , wherein the coating has a microstructure comprising primary boride and eutectic matrix, wherein a ratio of an amount of primary boride by volume to an amount of eutectic matrix by volume is below 0.3.

15 . Method of hardfacing a substrate, the method comprising the steps of:
providing a substrate; applying a coating to the substrate using an iron-based alloy composition according to claim 1 as a coating material.

16 . Method according to claim 15 , wherein the coating is applied by an overlay welding process.

Assignees

• Hoeganaes Ab Publ

Inventors

• Maroli Barbara
• Frykholm Robert
• Bengtsson Sven
• Frisk Karin

Classifications

• B22F1/05

  Metallic powder characterised by the size or surface area of the particles · CPC title

• C22C38/56

  with more than 1.7% by weight of carbon · CPC title

• C22C33/02

  by powder metallurgy · CPC title

• B23K9/04 Primary

  Welding for other purposes than joining, e.g. built-up welding · CPC title

• C22C38/46

  with vanadium · CPC title