Our new chromium(VI)-free blue passivating agent PROSEAL XZ 130 produces on electroplated zinc surfaces a sparkling blue passive film which is retained even after tempering at 200 °C. Passivation functions at room temperature and thus contributes to energy saving. The blue colour is achieved over a very wide working range at low batch concentrations of 3 – 7 l per 100 l. The passive layers provide very good corrosion protection which is retained even after a 24-hour thermal treatment at 120 °C. Due to temper resistance initial galvanising can be dispensed with and the parts are zinc plated, passivated and then tempered in one work cycle.
The illustrations show screws alkaline plated in TOPAS 3100 and passivated in PROSEAL XZ 130 before and after tempering (5hrs, 230°C).