Method for the preparation of a sintered body of high-hardness high-chromium cast iron

Abstract

Disclosed is a method for the preparation of a sintered body of a high-chromium cast iron of a specified chemical composition having greatly improved mechanical, abrasion-resistant and corrosion-resistant properties as compared with conventional cast bodies of the same cast iron. The inventive method comprises the steps of preparing a powder of the cast iron alloy by quenching solidification of a melt, e.g., by centrifugal spray atomization, and sintering the powder under compression by the discharge plasma sintering method.

What is claimed is:  
     
         1 . A method for the preparation of a sintered body of a high-chromium cast iron which comprises the steps of: 
 (a) subjecting a melt of a ternary alloy of iron, chromium and carbon containing from 11 to 30 mass % of chromium and from 2.2 to 5.0 mass % of carbon, the balance substantially being iron, to a quenching solidification treatment at a cooling rate not lower than 10 4°  C./second to give particles of the ternary alloy; and    (b) subjecting the particles of the ternary alloy to a sintering treatment under compression by the electric discharge plasma sintering method.    
     
     
         2 . The method for the preparation of a sintered body of a high-chromium cast iron as claimed in  claim 1  in which the quenching solidification of the alloy melt in step (a) is conducted by the centrifugal spray atomization method.  
     
     
         3 . The method for the preparation of a sintered body of a high-chromium cast iron as claimed in  claim 1  in which the pressure of compression in step (b) is in the range from 10 to 50 MPa.  
     
     
         4 . The method for the preparation of a sintered body of a high-chromium cast iron as claimed in  claim 1  in which the temperature of sintering in step (b) is in the range from 1000 to 1200° C.  
     
     
         5 . The method for the preparation of a sintered body of a high-chromium cast iron as claimed in  claim 1  in which the sintering treatment in step (b) is conducted in the atmospheric air.