Corrosion protection as a passion

A voestalpine expert speaks about corrosion protection

In the field of light-weight automotive design, the steels are becoming stronger and the sheets thinner. New material combinations and coatings are being used. Economic efficiency is required from engineering and design to production. Karl-Heinz Stellnberger, Manager of Corrosion Protection in Group Research, Steel Division, speaks about the contributions made by corrosion protection specialists at voestalpine.

Is corrosion protection research and testing able to keep up with the rapid developments in automotive engineering, or has it become a little rusty?

 Stellnberger: It is true that new materials, composite component designs and their joining techniques make it necessary to develop new types of intelligent corrosion protection. We at voestalpine are at the forefront, both in the field of materials development and corrosion protection.

I'm thinking of the developments presented by voestalpine at the Tri-country Corrosion Conference in Linz, for example zinc-magnesium coatings and the innovative voestalpine solutions in the field of press-hardened parts. 

The expertise of voestalpine in the field of steel and component production is generally well known. Why is this so?

Stellnberger: Decomposition caused by corrosion certainly means the end of life of materials. The only question is when. But we have always asked why.

„There are two decisive questions in the field of corrosion protection: when and why.“
While other experts were only concerned with determining the aspect of time in corrosion, we were already looking at the causal mechanisms. Comprehensive research and many years of experience are the foundations for our expertise. If you understand the processes, you can look at where and how to introduce changes in order to achieve better results.

That is one way in which we conduct basic research. We have also been successful in developing new testing methods that are capable of quickly providing the industry with true-to-life results. The longer a test takes, the more expensive it becomes.

„True-to-life results that can be achieved quickly and economically“

Which types of corrosion protection tests belong to the core competence of voestalpine?

Stellnberger: As in many areas of technology, simulation using mathematical models paired with true-to-life tests are becoming more and more relevant in the field of corrosion protection. Our simulations are similar to those in electrochemical corrosion tests that we have implemented in collaboration with our partners and customers with respect to specific parameters in order to be able to provide reliable data.

Who are your partners?

Stellnberger: We partner with leading OEMs as early as the product development phase and have been working closely for decades with corrosion experts at these companies. We test possible materials and give recommendations with respect to pretreatment, paint adhesion and steel grades.

We are also responsible for performing tests on components. OEMs send us selected components so that we can test them in our lab facilities. We test around 30,000 specimens every year. We work together with universities and educational institutions all over the world, including the French Corrosion Institute in France, Swera KIMAB in Sweden and the Austrian CEST Center of Competence for Electrochemical Surface Technology.

In addition to your daily work, you are also responsible for further developments in the field of corrosion protection for the entire industry, aren't you?

Stellnberger: You're certainly talking about our role in the Automotive Industry Association (Verband der Automobilindustrie = VDA). I am happy to say that the new cyclic corrosive environment lab test VDA 233-102, decisive parts of which were developed by our experts, is now the standard in the automotive industry. It beautifully simulates the practical behavior of corrosion, especially that of multi-metal materials such as steel, galvanized steel and aluminum. Now it is possible to simulate true-to-life corrosion effects on zinc-coated sheets to an extent previously not possible. The industry now has a lab test that takes comparatively little time and simulates the conditions to which materials and coatings are exposed.

Dr. Karl-Heinz Stellnberger manages the Corrosion Protection department in Group Research. After completing his apprenticeship in the chemistry lab of voestalpine and graduating from a technical college, he studied industrial engineering and completed his doctoral dissertation as part of an industrial project in the field of chromate-free pretreatment in Erlangen, Germany. He is well known in the industry for his expertise in the field of corrosion protection and sits on a number of specialist committees.