Cast iron, containing phosphorus
DoITPoMS, University of Cambridge
The presence of phosphorus in cast iron has no great effect on the graphite cementite ratio but serves to make the metal very fluid due to the creation of a low melting point phosphide eutectic. This may result in shrinkage porosity in large castings. Manganese serves to remove sulphur from the casting and since sulphur promotes cementite, the manganese will harden the iron.
Fe, C 3.46, Si 0.12, Mn 0.33, P 1.91, Cr 1.02 (wt%)
Reflected light microscopy
Dr R F Cochrane
Department of Materials, University of Leeds