Fine-grained high carbide cast iron alloys

Abstract

Embodiments of alloys having high, fine-grained carbide content, and methods of manufacturing such alloys. The alloys can be determined through the use of thermodynamic, microstructural, and compositional criterial in order to create a high strength and high toughness alloy. In some embodiments, the alloys can be used as a wear resistant component.

What is claimed is: 
     
         1 . A chromium white iron alloy comprising:
 a composition comprising Fe, Cr, and C, the composition being predominantly Fe;   wherein a total carbide and boride content in a microstructure of the alloy exceeds 40 volume %; and   wherein a melt temperature range of the alloy is below about 200° C.   
     
     
         2 . The chromium white iron alloy of  claim 1 , wherein the melt temperature range is below about 300° C. 
     
     
         3 . The chromium white iron alloy of  claim 1 , wherein the melt temperature range is below about 100° C. 
     
     
         4 . The chromium white iron alloy of  claim 1 , wherein the alloy can be formed into a sleeve or layer for use in pipelines designed to carry abrasive slurries. 
     
     
         5 . The chromium white iron alloy of  claim 1 , wherein a maximum carbide fraction is 50% mole fraction or higher. 
     
     
         6 . The chromium white iron alloy of  claim 1 , wherein a maximum carbide fraction is 60% mole fraction or higher. 
     
     
         7 . The chromium white iron alloy of  claim 1 , wherein the composition comprises, in weight %:
 Fe;   C: 3.2-4%;   Cr: 6-20%; and   W: 4-10%.   
     
     
         8 . The chromium white iron alloy of  claim 1 , wherein the composition comprises, in weight %:
 Fe;   C: about 2.5-about 3.8%;   Cr: about 10-about 28%;   Mn: about 0-about 1%;   Mo: about 0-about 1%;   Nb: about 0-about 5%;   Si: about 0-about 1%;   Ti: about 0-about 0.5%;   V: about 0-about 3%; and   W: about 0-about 9%.   
     
     
         9 . A wear resistant component comprising the chromium white iron alloy of  claim 1 . 
     
     
         10 . A method of manufacturing a chromium white iron alloy comprising:
 providing an alloy comprising Fe, Cr, and C, the alloy being predominantly Fe;   wherein a total carbide and boride content in a microstructure of the alloy exceeds 40 volume %; and   wherein a melt temperature range of the alloy is below about 300° C.; and   forming a component from the alloy.   
     
     
         11 . The method of  claim 10 , wherein a grain size of substantially all of the carbides does not exceed 50 micrometers in their longest dimension. 
     
     
         12 . The method of  claim 10 , wherein a total carbide content in the microstructure of the alloy exceeds 60 volume %. 
     
     
         13 . The method of  claim 10 , wherein the melt temperature range is below about 100° C. 
     
     
         14 . The method of  claim 10 , wherein forming the component comprises forming the component via a casting process. 
     
     
         15 . The method of  claim 10 , wherein the composition comprises, in weight %:
 Fe;   C: about 3.2-about 4%;   Cr: about 6-about 20%; and   W: about 4-about 10%.   
     
     
         16 . The method of  claim 10 , wherein the composition comprises in weight %:
 Fe;   C: about 2.5-about 3.8%;   Cr: about 10-about 28%;   Mn: about 0-about 1%;   Mo: about 0-about 1%;   Nb: about 0-about 5%;   Si: about 0-about 1%;   Ti: about 0-about 0.5%;   V: about 0-about 3%; and   W: about 0-about 9%.   
     
     
         17 . A chromium white iron alloy comprising:
 a composition comprising Fe, Cr, and C, the composition being predominantly Fe;   a maximum carbide fraction in the alloy which is thermodynamically stable at temperatures ranging from the room temperature to a temperature where the alloy is 100% liquid of 40% mole fraction; and   a segregated carbide fraction, defined as Fe, Cr-rich carbides existing at a temperature above the highest temperature at which an austenite or ferrite iron based matrix phase is thermodynamically stable, of 5% mole fraction or lower.