Quenching water aditives

The heat treatment of steels and cast irons of low temperability requires such a quick quenching that only the use of water as a quenching medium will be able to provide the hardness and necessary metallographic microstructure, so that the desired mechanical properties can be obtained at the parts.

When quenching a part from the austenitization temperature in water, a phenomenon called “Leidenfrost Effect” happens, and suddenly the part becomes involved by a vapor layer that acts as a thermal insulator. As the part becomes cooler, the adherent vapor layer breaks into bubbles. Since this does not happen uniformly and simultaneously over the whole surface of the part, there is the formation of “soft spots”, warpings and higher risks of cracks.

To avoid these problems, Durferrit has salts to be added to the water used as quenching medium in the hardening.

Durferrit salts, apart from reducing the formation of this vapor layer, provide reasonable protection against corrosion of treated parts and metallic components of the quenching system (tanks, pumps, valves, pipes, etc.).