Carbidic cast iron

Collective term for chilled, graphite-free cast iron.

The carbon is present chemically bonded in the form of carbide, which is why the break surface of the material appears whitish instead of gray. The carbides in unalloyed types of cast iron are mostly cementite (iron carbide Fe3C), with alloyed types of cast iron, the carbides that develop are chromium, niobium, molybdenum, or vanadium carbides. Depending on the composition, the metal matrix comprises ferrite, pearlite, martensite, or austenite. Figure 1 displays white carbidic cast iron, Figure 2 illustrates an impact failure of the same material.

Additional references:
Metal matrix of cast iron
Structure formation of cast iron
 

 

  • Fig. 1: White carbidic cast iron, 300:1
  • Fig. 2:  Impact failure of the iron material shown in Figure 1, 300:1