Ferrophosphorus is an alloy of iron and phosphorus. It contains high proportion of iron phosphides, Fe2P and Fe3P. The usual grades contain either 18 or 25% of phosphorus. It is a gray solid material with melting point between 1050-1100 °C. It may liberate phosphine in contact with water. Very fine powder can be combustible.
1. Used in metallurgy as a source of phosphorus for alloying, for deoxidizing the melt and for removal of unwanted compounds into slag.
2. Addition of ferrophosphorus is used to produce powder metallurgy (P/M) steels with favorable magnetic properties, e.g. high saturation induction. Iron phosphide acts here as a solid solution hardener and a sintering aid.
3. Can be added to cast iron, where the phosphorus improves fluidity and therefore quality of the castings, can increase wear resistance and cutability. In steels its addition to some alloys can improve corrosion resis