Verfahren zur Behandlung von entfetteten und mit einer sauren Loesung gebeizten Metallober-flaechen vor dem Emaillieren

A pickled steel sheet is treated with a solution containing alkanolamines with at least 3 alkanol groups, and an alkali before enamelling. In an example (parts and percentages by weight) a steel sheet that has been pickled in HCl with a content of 6% of ferrochloride is rinsed and then immersed at room temperature in a solution containing 2% of a mixture of 40 parts of caustic soda, 40 parts of triethanolamine and 20 parts of tetrasodium E.D.T.A. The sheet is finally rinsed and then passivated in a 1% solution of 60 parts soda, and 40 parts of trisodium phosphate. Borax may also be used in the passivating solution. Other alkanolamines that may be used are triisopropanolamine, and polyalkanol.