Process of phosphating steel and/or galvanized steel before painting

Abstract From the Canadian patent

In a process of phosphating metal surfaces of galvanized steel or of galvanized steel and aluminum, before a painting the, metallic surfaces are treated at a temperature between 40 and 60°C with an aqueous phosphating solutions which contain 0.4 to 5.0 g/l Mg, 0.05 to 2.0 g/l Ni, 8 to 20 g/l P2O5 and at least one oxidizing agent and wherein the ratio of free acid to total acid is (0.02 to 0.15) : 1. Where aluminum is absent the metallic surfaces are treated with phosphating solutions which when used in a spraying process are adjusted to contain between 0.4 and 1.0 g/l zinc and when used in a spraying-dipping process and in a dipping process are adjusted to contain between 0.9 and 1.5 g/l …