Metallgesellschaft Aktiengesellschaft

Klaus Wittel

Werner Rausch

Gerhard Muller

Klaus Bittner

Joachim Geldner

Dieter Jentsch

Georg Blumlhuber

Margit Fleischhacker-Jeworrek

Georg Bluemlhuber

Process for removing soap-contaminated conversion layers on metal

Disclosed is a process in which a phosphate layer is formed on a metal surface in preparation for the subsequent application of a vitreous enamel coating, wherein a phosphating solution is used which contains essentially nickel and/or cobalt as a layer-forming cation in amounts of 0.5 to 3 g/l as well as

Preparation of metal surfaces for vitreous enameling

In a process of cleaning metal surfaces with aqueous alkaline cleaning solutions, which contain silicates and surfactants and are recycled after ultrafiltration, a solution is employed which contains silicate only as a sodium silicate and/or potassium silicate of the formula Na.sub.2 O.2SiO.sub.2.xH.sub.2 O and/or K.sub.2 O.2SiO.sub.2.xH.sub.2 O. The cleaning solution is preferably adjusted to a pH value between 7 and 12 and to a concentration (expressed as SiO.sub.2) of 0.1 to 20, particularly 0.5 to 10 g, silicate per liter.

Process for cleaning metal surfaces

Disclosed is a process for phosphating a galvanized surface, particularly of galvanized steel wherein the surface is contacted for up to 10 seconds with a phosphating solution which contains accelerator, particularly nitrate,

Phosphating process

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Frankfurt-am-Main, Germany

Klaus Wittel