HIGH-CHROMIUM WHITE IRON ALLOY COMPRISING RARE-EARTH

Abstract

The present disclosure relates to a high-chromium white iron alloy comprising rare-earth (RE) element. The alloy comprises RE of 0.01-0.6 wt %, Cr of 26-30 wt %, C of 2.5-4 wt %, Si of 0.2-2 wt %, Mn of 0.5-1 wt %, Mo of 0.2-0.5 wt %, Ni of 0.01-0.6 wt %, at most 1 wt % of impurities, and a balance of Fe. The invention also relates to a white iron product made from the alloy. Further, the invention relates to a method comprising adding an RE powder to a metal melt comprising Cr, C, Si, Mn, Mo, Ni and Fe as above, whereby a white iron alloy melt comprising RE is formed.

Claims

1. A high-chromium white iron alloy comprising a rare-earth (RE) element, the high-chromium white iron alloy containing: RE: 0.01-0.6 wt %, Cr: 26-30 wt %, C: 2.5-4 wt %, Si: 0.2-2 wt %, Mn: 0.5-1 wt %, Mo: 0.2-0.5 wt %, Ni: 0.01-0.6 wt %, at most 1 wt % of impurities, and a balance of Fe.

2. The high-chromium white iron alloy of claim 1, wherein the RE element comprises Ce, La and Y.

3. The high-chromium white iron alloy of claim 1, containing Fe within the range of 60-70 wt %.

4. A method of preparing a high-chromium white iron alloy comprising rare-earth (RE) element, the method comprising: adding an RE powder to a metal melt whereby a white iron alloy melt comprising RE is formed, the white iron alloy melt containing: RE: 0.01-0.6 wt %, Cr: 26-30 wt %, C: 2.5-4 wt %, Si: 0.2-2 wt %, Mn: 0.5-1 wt %, Mo: 0.2-0.5 wt %, Ni: 0.01-0.6 wt %, at most 1 wt % of impurities, and a balance of Fe.

5. The method of claim 4, wherein the RE powder has a particle size distribution between 0.2 and 7 mm.

6. The method of claim 4, wherein the RE powder has an RE content within the range of 25-40 wt %.

7. The method of claim 4, wherein the RE powder comprises mischmetal.

8. The method of claim 4, further comprising: with the white iron alloy melt, casting a product by line forming, shell forming, hand forming or by 3D-printed moulds or cores, to obtain a white iron product.

9. The method of claim 4, wherein the white iron product is or comprises any of a dispersing disc, a grinding disc, a refiner disc, an abrasion resistant plate, a mixing blade, a mixing arm or a cutting blade.

10. A white iron product comprising a high-chromium white iron alloy containing a rare-earth (RE) element, the high-chromium white iron alloy containing: RE: 0.01-0.6 wt %, Cr: 26-30 wt %, C: 2.5-4 wt %, Si: 0.2-2 wt %, Mn: 0.5-1 wt %, Mo: 0.2-0.5 wt %, Ni: 0.01-0.6 wt %, at most 1 wt % of impurities, and a balance of Fe. wherein the white iron product is or comprises any of a dispersing disc, a grinding disc, a refiner disc, an abrasion resistant plate, a mixing blade, a mixing arm or a cutting blade.

11. The high-chromium white iron alloy of claim 1, containing: RE: 0.2-0.4 wt %.

12. The high-chromium white iron alloy of claim 1, containing: Cr: 27-29 wt %.

13. The high-chromium white iron alloy of claim 1, containing: C: 2.5-3.2 wt %.

14. The high-chromium white iron alloy of claim 1, containing: Si: 0.3-1 wt %.

15. The high-chromium white iron alloy of claim 1, containing: Mn: 0.8-1 wt %.

16. The high-chromium white iron alloy of claim 1, containing: Mo: 0.4-0.5 wt %.

17. The high-chromium white iron alloy of claim 1, containing: Ni: 0.2-0.4 wt %.

18. The white iron product of claim 10, containing: RE: 0.2-0.4 wt %.

19. The white iron product of claim 10, containing: Cr: 27-29 wt %.

20. The white iron product of claim 10, containing: C: 2.5-3.2 wt %.

Description

DETAILED DESCRIPTION

[0015] Embodiments will now be described more fully hereinafter. However, other embodiments in many different forms are possible within the scope of the present disclosure. Rather, the following embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0016] In some embodiments, the amount of RE in the alloy, product or alloy melt is within the range of 0.05-0.6 wt % or 0.1-0.5 wt %, preferably within the range of 0.2-0.4 wt % which may be a preferred range in some embodiments.

[0017] In some embodiments, the amount of chromium (Cr) in the alloy, product or alloy melt is within the range of 27-29 wt %, which may be a preferred range in some embodiments.

[0018] In some embodiments, the amount of carbon (C) in the alloy, product or alloy melt is within the range of 2.5-3.2 wt %, which may be a preferred range in some embodiments.

[0019] In some embodiments, the amount of silicon (Si) in the alloy, product or alloy melt is within the range of 0.3-1 wt %, which may be a preferred range in some embodiments.

[0020] In some embodiments, the amount of manganese (Mn) in the alloy, product or alloy melt is within the range of 0.8-1 wt %, which may be a preferred range in some embodiments.

[0021] In some embodiments, the amount of molybdenum (Mo) in the alloy, product or alloy melt is within the range of 0.4-0.5 wt %, which may be a preferred range in some embodiments.

[0022] In some embodiments, the amount of nickel (Ni) in the alloy, product or alloy melt is within the range of 0.2-0.4 wt %, which may be a preferred range in some embodiments.

[0023] There is typically a small amount of inevitable impurities in the alloy, product or alloy melt, e.g. if the iron (Fe) is from scrap metal. The amount of impurities is preferably at most 1 wt %. The at most 1 wt % of impurities typically comprises a plurality of compounds other than those specifically specified herein as part of the alloy or alloy melt, e.g. copper (Cu) resulting from using scrap metal as an iron source. Each of said compounds comprised in the at most 1 wt % of impurities, e.g. Cu, is typically present in an amount of less than 0.5 wt % or less than 0.2 wt %, preferably less than 0.1 wt % or less than 0.05 wt % of the alloy or alloy melt.

[0024] In some embodiments, the RE comprises or consists of cerium (Ce), lanthanum (La) and/or yttrium (Y), preferably Ce (which is easily obtainable).

[0025] The balance of the alloy, product or alloy melt is Fe. In some embodiments, the alloy, product or alloy melt comprises Fe within the range of 60-70 wt %.

[0026] RE powder is added to the metal melt to produce the alloy melt of the present disclosure. The RE powder may have a particle size distribution between 0.2 and 7 mm. The RE powder may have an RE content within the range of 25-40 wt %. The RE powder may comprise or consist of so called mischmetal.

[0027] The alloy melt may be used for casting a product, to obtain a white iron product. The casting is preferably by line forming, shell forming, hand forming or by 3D-printed moulds or cores. Line forming may be preferred, but shell forming has been seen to give primary austenite formation which may be desirable in some embodiments.

[0028] In some embodiments, the white iron product is or comprises any of a dispersing disc, a grinding disc, a refiner disc, an abrasion resistant plate, a mixing blade, a mixing arm or a cutting blade, preferably a dispersing disc, a grinding disc or a refiner disc, most preferably a dispersing disc.

[0029] The present disclosure has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the present disclosure, as defined by the appended claims.