Zirconium is a multi-functional element as it acts as a deoxidizer, desulfurizer and denitrizer. It prevents other elements (vanadium and boron) from interacting with oxygen and nitrogen. Additions of zirconium as well as titanium to the melt result in the formation of carbosulfides.
Zirconium also combines with other elements to form Zr(N,C), ZrSx or Zr4S2C2.Due to its significant affinity to nitrogen, zirconium can force nitrogen out of aluminum nitrides. Interaction of ZrN with (Zr,Mn)S results in the formation of inclusions having the shape of angular crystals. Zirconium carbonitrides also form as thin layers around sulfides.
Zirconium is used as a microalloying element to increase the strength, toughness, wear- and corrosion resistance, hardenability, weldability and workability of steels.
The INSTEEL®11 modifier has shown high efficiency when used for producing heavy-duty cast products utilized for the manufacturing of rolling stock for the Russian Railways (railway carriage frames and beams). It increased the impact strength of steels at low temperatures (KCV-60°).