Sep 30 2008
For the past year, voestalpine Stahl GmbH has been passivating its galvanized flat steel with Lugalvan® Passivation, the first heavy-metal-free and fluoride-free conversion coating product for galvanized flat steel. The environment friendly BASF anticorrosion product was developed into a ready-to-market product jointly by the two companies. For voestalpine customers, the use of this new type of passivation reduces the process costs: steel strip protected in this way can directly be painted, so further processing can become more economical.
“We have had very good experience with Lugalvan Passivation. Our customers are very happy with this new kind of corrosion protection,” explains Karl-Heinz Stellnberger, Head of Development Corrosion/Corrosion Protection at voestalpine in Linz, Austria. “Lugalvan Passivation is not only a passivating agent, but also a multifunctional layer: galvanized flat steel protected in this way can directly be painted without any further pretreatment. As a result, the process costs for further processing at our customers are reduced. The nanometer-thick passivation layer serves both as corrosion protection during transportation and as adhesion intermediate. In addition, it also improves the formability properties of the galvanized steel strip.
“We have encountered a positive response worldwide to our polymer-based, heavy-metal-free anticorrosion product. At present, we are running plant trials with Lugalvan Passivation at the sites of several well-known international steel producers,” says Dr. Fabio Nicolini, Head of Global Business Management Metal Surface Treatment at BASF. “It is applied with the same machinery as conventional anticorrosion products based on chromium salts. Therefore it is possible to change to the environment friendly product within a few days.” BASF has also developed an “in-situ method” which allows its customers to control the passivation quality. “With an optical sensor fitted at a distance of about ten centimeters to the metal strip, it is possible to ensure reliable and sustainable operation and complete quality assurance,” says Dr. Helmut Witteler, head of Global Product Development Polymers at BASF.
The new anticorrosion system from BASF is very robust: contamination of the metal strip or the Lugalvan solution with skin passing emulsions impairs neither the visual appearance nor the anticorrosion property of the galvanized steel strip.
At Euroblech (the “International Metal Sheet Working Technology Exhibition”), which takes place in Hanover, Germany, October 21 through 25, 2008, BASF will be demonstrating Lugalvan Passivation and the quality assurance procedure at booth B12 in Hall 12.