Zirconium is a rare metal. Its melting point (1852 + 2) ℃. It's a carbide forming element. Zirconium is a powerful deoxidization and denitrification element in the process of steelmaking. Zirconium can refine the austenite grains of steel, which can be combined with sulphur to form zirconium sulfide, thus preventing the hot brittleness of steel.
(1) effect of zirconium on microstructure and heat treatment of steel
Zirconium has refining effect on annealing structure of pure iron and carbon steel. For high carbon steel, it can promote the spheroidization of carburized body. Zirconium is one of the elements that prevents the austenite from growing at high temperatures. With regard to the relation of zirconium to hardenability, if zirconium (as an alloy element) is solidly dissolved in austenite, it has a significant effect on the increase of hardenability. Zirconium increases hardenability secondary to boron and between titanium and vanadium.
(2) influence of zirconium on process performance
The effect of zirconium on thermal processing performance is one of the effective elements to prevent hot brittleness since zirconium formed with sulfur. Adding a small amount of zirconium significantly improves the cutting life of low tempering high carbon tool steel.
