Hot-dip galvanizing of steel products is perhaps the best method of protection against the impact of the environment and corrosion. A properly performed hot-dip galvanizing process ensures effective protection for 30-50 years, provided that the protective surface is inspected and local damage is repaired on a regular basis.
Hot-dip galvanizing consists in submerging the prepared product in a zinc bath at the temperature of about 450°C. After the product is submerged, as a result of chemical and physical reactions, the surface becomes activated. Next, as a result of bidirectional diffusion, intercrystalline Fe-Zn phases are formed, and the subsequently formed phases are covered with zinc alloy.
When galvanized elements are affected by the atmosphere, zinc oxide is formed first, later transforming into zinc hydroxide, which in turn transforms into basic zinc carbonate in the presence of carbon dioxide. This is how the protective layer is formed. The formation of protective layers takes several days up to several months, depending on the conditions.
Smooth performance of the order and excellent parameters of the zinc coating can only be obtained with mutual cooperation and understanding of the ordering party and the galvanizing shop. The ordering party is responsible for preparing items for galvanizing. The galvanizing process should be planned and taken into account already at the product design stage. It is about taking into consideration the stress generated upon submerging the item in the zinc bath, ensuring free inflow of zinc and outflow of air (inflow and vent holes). Part design should make it possible to suspend it reliably and quickly before the galvanization.
Due to safety considerations, the design should not have any closed (welded) areas where air could remain. A sudden pressure increase at a high temperature may cause the galvanized part to rupture. Such situations pose a serious hazard to the employees of the galvanizing shop.
Experienced galvanizing shop
WIŚNIOWSKI does not only have its own in-house galvanizing shops, but also a service galvanizing shop in Nowy Sącz. Our galvanization process uses a technological line sized 7,500×1,500×2,800 mm, which makes it possible to apply protective coating onto steel structures with dimensions up to 7,000×1,400×2,500 mm and with the maximum weight of 2.0 t. We are one of the largest galvanizing shops in Lesser Poland. We have been galvanizing steel structures for our customers for over 20 years. This experience and our developed technological line enable us to offer services of the highest quality.
Shop Director WIŚNIOWSKI
Smooth, even, and perfectly adhering zinc coating can be obtained only when the surface of the galvanized part is appropriately prepared. It is primarily about removing all the unnecessary residues after previous manufacturing stages, e.g.: risers, burrs, dust, varnishes (also the ones used for marking and numbering parts). If parts were sanded beforehand, they should be thoroughly rinsed, blown with compressed air and cleaned, because the sand or other abrasive substance residues make their way to the zinc bath and pollute it. The ordering party should also consider the fact that holes, especially threaded holes may require further machining after being poured with zinc.
The WIŚNIOWSKI hot-dip galvanizing shop has been operating successfully since 1996. It boasts great, long-standing cooperation with multiple partners, not only from the region, but also from outside its boundaries. The shop is open to high expectations and readily undertakes hot-dip galvanization of complex elements. The positive effects of these efforts frequently result in loyal cooperation based on partnership.
The galvanizing shop operates using an integrated quality management system. It has received prestigious certificates – Quality Management in accordance with ISO 9001:2008 and Occupational Health and Safety Management in accordance with OHSAS 18001:2007.
For the last dozen or so years, the WIŚNIOWSKI galvanizing shop has been a member of the Polish Galvanizers Association. By taking advantage of the experience gathered during over twenty years of activity, the galvanizing shop continues to specialize in providing hot-dip galvanizing services at the highest level. The technological process is carried out using components produced by globally recognized manufacturers. In order to provide comprehensive service to the customers, the galvanizing shop also offers powder coating of previously galvanized structures.
WIŚNIOWSKI cares about its finished galvanized products and this is why we also offer steel whose chemical composition best corresponds to the hot-dip galvanizing conditions. It is crucial to obtaining high quality galvanization.
By: Piotr Kołaczek