Alloy compositions suitable for molten magnesium environments

Abstract

A castable and machinable alloy suitable for submersion in a molten magnesium or magnesium aluminum melt has the following composition: ELEMENT CONTENT (weight %) Boron 0.01-2.0  Carbon 0.01-2.0  Sulphur Trace Phosphorus Trace Chromium  5.0-15.0 Silicon 0.0-2.0 Molybdenum  2.00-12.00 Tungsten  0.5-10.00 Vanadium 0.5-5.0 Niobium 0.5-5.0 Cobalt  0.5-10.0 Iron Balance The alloy is resistant to dissolution by the melt at temperatures of up to around 1800° F.

1 . a component of a molten magnesium pump selected from the group comprising an impeller, a bearing, a support post, a shaft, and a pump housing, being comprised of an alloy including iron, chromium, molybdenum, vanadium, niobium, cobalt and tungsten, and at least one of boron and carbon, the alloy being essentially free of sulfur and phosphorus. 
   
   
       2 . The alloy of  claim 1 , wherein the carbon is at a concentration is 0.4 to 2.0 weight %. 
   
   
       3 . The alloy of  claim 2 , wherein the carbon concentration is 0.5-0.6 weight %. 
   
   
       4 . The alloy of  claim 1 , wherein the boron is at a concentration of 0.15 to 0.50 weight %. 
   
   
       5 . The alloy of  claim 4 , wherein the boron concentration is 0.20-0.30 weight %. 
   
   
       6 . The alloy of  claim 1 , wherein the sulphur is at a concentration of less than about 0.005 weight %. 
   
   
       7 . The alloy of  claim 1 , wherein the phosphorus is at a concentration of less than about 0.005 weight %. 
   
   
       8 . The alloy of  claim 1 , wherein the chromium is at a concentration of 9 to 12 weight %. 
   
   
       9 . The alloy of  claim 8 , wherein the chromium concentration is 10 to 11 weight %. 
   
   
       10 . The alloy of  claim 1 , wherein the alloy further includes silicon at a concentration of less than about 1.0 weight %. 
   
   
       11 . The alloy of  claim 1 , wherein the silicon concentration is less than about 0.8 weight %. 
   
   
       12 . The alloy of  claim 1 , wherein the molybdenum is at a concentration of 5.0 to 8.0 weight %. 
   
   
       13 . The alloy of  claim 12 , wherein the molybdenum concentration is 6.0 to 7.0 weight %. 
   
   
       14 . The alloy of  claim 1 , wherein the tungsten is at a concentration of 2.5 to 4.0 weight %. 
   
   
       15 . The alloy of  claim 16 , wherein the tungsten concentration is 3.0 to 3.5 weight %. 
   
   
       16 . The alloy of  claim 1 , wherein the vanadium is at a concentration of 1.5 to 3.0 weight %. 
   
   
       17 . The alloy of  claim 16 , wherein the vanadium concentration is 2.00 to 2.40 weight %. 
   
   
       18 . The alloy of  claim 1 , wherein the niobium is at a concentration of 2.0 to 4.0 weight %. 
   
   
       19 . The alloy of  claim 18 , wherein the niobium concentration is 2.80 to 3.20 weight %. 
   
   
       20 . The alloy of  claim 1 , wherein the cobalt is at a concentration of 3.0 to 5.0 weight %. 
   
   
       21 . The alloy of  claim 20 , wherein the cobalt concentration is 4.00 to 4.50 weight %. 
   
   
       22 . The alloy of  claim 1 , further including tantalum at concentration of less than about 1.5 weight %. 
   
   
       23 . The alloy of  claim 1 , further including manganese at a concentration of about 0.5-1.0%. 
   
   
       24 . The alloy of  claim 1 , wherein the alloy is substantially free of nickel. 
   
   
       25 . The alloy of  claim 24 , wherein the alloy includes less than about 0.005 weight % nickel.