Refining nickel base superalloys
AssigneeSpecial Metals Corporation
InventorClaudia J. Burton
Life of this patent
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Abstract
A process for producing a low iron nickel base superalloy having a very low selenium content. The process includes the steps of: preparing a superalloy melt containing, by weight, at least 60% nickel, no more than 1% iron, and more than 0.0004% selenium; maintaining the melt in contact with a calcium and/or magnesium bearing substance for a period of time sufficient to allow for reaction between selenium and calcium and/or magnesium, and a lowering of said melt's selenium content to a level below 0.0003%, said selenium removal being carried out in a substantially oxygen free atmosphere; casting the melt; and heat treating the cast metal.
Claims6
In a process for producing a low iron, nickel base superalloy, which process includes the steps of preparing a superalloy melt containing, by weight, at least 60% nickel, no more than 1% iron, and more than 0.0004% selenium;
- casting said melt;
- and heat treating the cast metal;
- the improvement comprising the steps of maintaining said melt in contact with a calcium and/or magnesium bearing substance for a period of time sufficient to allow for reaction between selenium, and calcium and/or magnesium, and a lowering of said melt's selenium content to a level below 0.0003%, said selenium removal being carried out in a substantially oxygen free atmosphere, said reacted selenium accumulating as slag on the surface of said melt, said selenium-bearing slag being separated from said melt prior to solidification of said melt.
Dependencies are inferred from the claim text.