Iron alloy containing molybdenum

Abstract

An iron alloy comprises 1.5-4.5% carbon, 1.5-4.5% silicon, at least 1.0 to 6.5% molybdenum and optionally copper and/or nickel wherein (% Mo+% Ni+% Cu) does not exceed 6.5%, balance iron and incidental impurities. The alloy is preferably spheroidal graphite cast iron. The alloy is especially useful in manufacturing brake disc rotors.

1 . An iron alloy comprising, by weight, 1.5 to 4.5% carbon, 1.5 to 4.5% silicon, 1.2% to 6.5% molybdenum, optionally nickel and/or copper and wherein (% molybdenum+% nickel+% copper) does not exceed 6.5%, balance iron and incidental impurities.  
     
     
         2 . An iron alloy as claimed in  claim 1  wherein the alloy is a spheroidal graphite cast iron.  
     
     
         3 . An iron alloy as claimed in  claim 1  or  claim 2  wherein carbon is present in an amount of from 1.5 to 3.8%.  
     
     
         4 . An iron allay as claimed in  claim 1  or  claim 2  wherein carbon is present in an amount of 3.0 to 3.5%.  
     
     
         5 . An iron alloy as claimed in any one of the previous claims wherein carbon is present in an amount of from 30 to 3.35%.  
     
     
         6 . An iron alloy as claimed in any one of the previous claims wherein silicon is present in an amount of from 1.9 to 2.58%.  
     
     
         7 . An iron alloy as claimed in any one of the previous claims wherein silicon is present in an amount of from 2.1 to 2.3%.  
     
     
         8 . An iron alloy as claimed in any one of the previous claims wherein molybdenum is present in an amount of from 1.2 to 4.5%.  
     
     
         9 . An iron alloy as claimed in any one of the previous claims wherein molybdenum is present in an amount of from 1.2 to 3.0%.  
     
     
         10 . An iron alloy as claimed in any one of the previous claims wherein nickel is present in an amount of from 0.1 to 4.5%.  
     
     
         11 . An iron alloy as claimed in any one of the previous claims wherein nickel is present in an amount of from 0.1 to 3.5%.  
     
     
         12 . An iron alloy as claim in any one of the previous claims wherein nickel is present in an amount of about 1.0%.  
     
     
         13 . An iron alloy as claimed in any one of the previous claims wherein copper is present in an amount of from 0.1 to 4.5%.  
     
     
         14 . An iron alloy as claimed in any one of the previous claims wherein copper is present in an amount of from 0.1 to 3.5%.  
     
     
         15 . An iron alloy as claimed in any on of the previous claims wherein copper is present in an amount of about 1.0%.  
     
     
         16 . An iron alloy as claimed in any one of  claims 1  to  8  wherein the alloy is essentially fee of nickel.  
     
     
         17 . An iron alloy are claimed in any one of  claims 1  to  8  wherein the alloy has substantially no copper.  
     
     
         18 . An iron alloy as claimed in any one of the previous claims wherein the alloy contains a small amount of alloying elements from a spheroidizing agent.  
     
     
         19 . An iron alloy as claimed in any one of the previous claims wherein the alloy is essentially free of other alloying elements.  
     
     
         20 . An iron alloy comprising 3 to 3.5% carbons 1.9 to 2.58% silicon and 1.2 to 1.5% molybdenum, balance iron and incidental impurities, the alloy being a spheroidal graphite cast iron.  
     
     
         21 . An iron alloy comprising 3 to 3.35% carbon, 1.9 to 2.58% silicon and about 3.0% molybdenum, balance iron and incidental impurities, the alloy being a spheroidal graphite cast iron.  
     
     
         22 . An iron alloy as claimed in  claim 1  comprising from 3.5 to 4.5% carbon, from 2.1 to 2.3% silicon and from 2.5 to 3.5% molybdenum, balance iron and incidental impurities.  
     
     
         23 . An iron alloy as claimed in  claim 22  wherein molybdenum is present in an amount of about 3.0% and carbon is present in an amount of 3.7%.  
     
     
         24 . An iron alloy as claimed in any one of the previous claims wherein the weight percentage of the incidental impurities does not exceed 0.8%.  
     
     
         25 . An iron alloy as claimed in  claim 22  wherein the incidental impurities include up to 0.04% sulphur and up to 0.04% phosphorus.  
     
     
         26 . An iron alloy comprising from 1.5 to 4.5% carbon, from 1.3 to 4.5% silicon, from 1.2 to 4.5% molybdenum, up to 0.2% of a spheroidizing agent, balance iron, and wherein other elements are present only in impurity amounts.  
     
     
         27 . A process for the production of an iron alloy as claimed in any one of  claims 1  to  27  comprising the steps of 
 a) providing a melt containing iron, silicon, carbon, molybdenum and optionally copper and/or nickel; and  
 b) casting the melt.  
 
     
     
         28 . A process as claimed in  claim 27  wherein step (a) comprises the step of melting a cast iron or a steel, a ferro silicon alloy, a recarburiser and a ferromolybdenum alloy.  
     
     
         29 . A process as claimed in  claim 28  or  claim 29  the melt is treated with a spheroidizing agent to cause any chemically uncombined carbon in the coded alloy to be present in the form of spheres.  
     
     
         30 . A process as claimed in any one of  claims 28  to  30  wherein step (a) is carried out at a temperature in excess of 1350° C.  
     
     
         31 . A process as claimed in any one of  claims 28  to  31  wherein the casting step occurs before fade takes place.  
     
     
         32 . A disc broke rotor manufactured wholly or partly from an iron alloy as claimed in any one  claims 1  to  27 .