Ferro-Zirconium or more accurately, Zirconium-Iron (80% Zr: 20% Iron), is a master alloy used in the production of stainless steels, special steels and some cobalt and nickel-base superalloys. As with copper-zirconium, this master alloy is a means by which Zirconium is added to an alloy.
Zirconium is a strong grain refiner but also acts as a ‘getter’ of nitrogen, sulphides and oxides while aiding carbide formation. The addition of Zirconium improves impact resistance, yield strength and hardenability (a measure of the capacity of steel to be hardened in depth when quenched from its austenitic temperature).
At Lipmann Walton & Co Ltd, we commission production of 5x50mm FeZr lumps through our partners. We focus on tin-free FeZr by carefully controlling the Zirconium raw materials selected for re-melting, though tin-bearing FeZr is also available.
Ferro-Zirconium master alloy can be easily confused with Ferro-Silicon-Zirconium, with dramatic effects. It is thought that a contributing factor in the Deepwater Horizon oil spill could have been the misuse of FeSiZr alloy instead of FeZr, which would have weakened components in the pipework. FeSiZr contains less than half the Zirconium content of FeZr master alloy.
Recent novel applications of special steels made with FeZr are exploited in certain amorphous alloy formulations. These applications are industrial hardware components for civil and marine construction, plant boiler tubes, gears and so forth as well as protective coatings for industrial machinery such as pipelines.