On the basis of finding that lead is the vital factor to bring patina on galvanized steel sheets, two hypothesizes, colloid film of lead sulfate and the codeposition of zinc and lead, were employed.

• 在发现铅是导致电镀锌钢板黑变发生的关键因素的基础上,对电镀锌钢板的黑变机理提出了锌铅共沉积假说和硫酸铅胶体膜假说;