Automotive Industry Traffic Restraint Systems: MicroZINQ in Ten-Year Practical Test
Cost-intensive investments or extensive repairs are not necessary - with piece galvanizing, there is a very effective process to protect steel from corrosion for decades.
Until today, users from the automotive sector were unable to use piece galvanizing because, despite superior corrosion protection properties, it did not meet the requirements in other functional areas. These include ductility, weight or formability. Finally, a joint development project with an automobile manufacturer resulted in the thin-film piece galvanizing process microZINQ, which was brought to series maturity and launched on the market in 2004. The introduction into the overall market of the metalworking industry took place with the expansion of capacity in 2015 at the microZINQ location in Hagen (among other things with the support of the state of North Rhine-Westphalia as well as the European Union from the European Fund for Regional Security in the amount of approx. 1.7 million euros). The very high resistance of the zinc-aluminum layer (Zn5Al), already known from previous applications, has now been confirmed once again by a long-term test with steel crash barriers.
In May 2009, an approximately 150-metre long test track on the BAB48 motorway was equipped with a microZINQ galvanized restraint system, and since then the components have been regularly checked. After 10 years of practical testing under common stresses such as rockfall and road salt, the following interim conclusion was reached in spring 2019:
- with regard to the general visual appearance, all components have a uniform matt light grey colour, just as in previous years.
- all components are in very good condition along the entire route.
- there are no rusty spots.
- the zinc coating covers all edges and is undamaged.
- no zinc erosion can be detected over the ten years. The (supposedly) determined increase of the zinc layer thickness of 1.3 µm on average can be explained against the background of reaction and deposition products forming.
"Our result is fully in line with the findings of a long-term study by the Federal Highway Research Institute, in which strip galvanized material with zinc and Zn5Al coatings was examined. The coatings behave the same, regardless of the galvanizing process. However, piece galvanizing offers the advantage of a completely closed zinc coating, in contrast to strip galvanizing, which has non-galvanized cut and punched edges for production reasons," says Dr. Thomas Pinger, Head of Research and Development at ZINQ.
"In view of the urgently required investments in the infrastructure, in which, according to the current draft of the climate protection law of the Federal Government, the public authorities are to take on a model function and the environmental impact will play a decisive role over the entire service life, microZINQ thus offers an excellent solution for the corrosion protection of steel parts on and along roads, which has been proven in long-term tests".