2 illustrates the basic Thermex plant as installed in a rolling mill. Directly after leaving the last rolling mill stand the
bar is passed through a special cooling pipe system where it is rapidly water quenched for a short time depending on the size
of bar and the rolling speed. The rolling strand, which is cut to cooling bed length by suitable rotary shears, is fed to
cooling bed and the finishing
shop in the well-known manner.
High Pressure Water Station
The result of the rapid quenching in Thermex is a hardened structure
of the surface. After leaving the cooling line the heat in the core of the bar reheats the surface up to an equalising temperature
thus tempering the martensite surface. The resulting heat-treated structure has high strength and good toughness properties.
The microstructure of the core is a very fine-grained ferrite and pearlite.