The Nickel Zinc (NiZn) galvanizing process is a solution to the problem that occurs during the hot dip galvanizing process of silicon-containing steels. These reactive steels exhibit a higher rate of alloy growth ("Sandelin effect") during the galvanizing process, leading to thicker coats, poor adhesion and a poor surface appearance.
The Nickel in the NiZn alloy helps suppress this reactive coating tendency in these types of steels with up to 0.20% Silicon. Nickel contents in NiZn galvanizing baths can range from 0.05 to 0.14%, but typically on the lower end of this range due to issues with excessive dross and rough surface when casting with higher nickel baths.
