When stainless steel meets steel screws, contact corrosion is inevitable: The more noble metal attacks the "less noble" one. Galvanizing the stainless steel beforehand provides a remedy, but it is not easy: the galvanic process is not suitable for all stainless steels, and there is often a lack of adhesion. OTH Hagen now also provides a reliable solution for the electrolytic galvanizing of stainless steel: The surface specialist applies an intermediate layer of nickel. This achieves a significantly stronger adhesion of the metals.
Process parameters adapted and technology supplemented
The new process variant requires a precise and well thought-out procedure: "We first apply the nickel from a specially adapted electrolyte, only then does the zinc layer follow. It is important that the nickel does not become passive before the zinc bath," explains OTH Managing Director Udo Gensowski. The surface specialists also adjust the specific process parameters of the zinc bath. The technology has also been updated for optimized stainless steel galvanizing: "We have supplemented our zinc drum system and integrated the process sequence into the existing system with a high-performance control system," says Gensowski.
Great benefits: many applications benefit
The galvanizing of stainless steel has long been an issue at OTH Hagen. The benefits of the new process are all the greater. For example, customers require non-corroding stainless steel screws for steel scaffolding. There are also numerous applications in equipment manufacturing and the automotive industry that will benefit from stainless steel treated with nickel and zinc in the future.
