Hot-Dip Galvanized Strip
We process input material into galvanized strip steel with zinc coatings of between 50 and 1,200 g/m2, which corresponds to a zinc coating thickness of 3.5 µm to 84 µm. In doing so, we align dimensional tolerances and material grades exactly to the needs of our customers. At our processing locations for flat steel we have high-performance slitting lines in which we process strip thicknesses from 0.95 to 6.00 mm in widths of 20 - 1,650 mm.
Detailed information on the delivery programs of our hot-dip galvanizing plants can be found on the right.
What is meant by "hot dip galvanizing"?
Hot-dip galvanizing" describes the metallic coating of steel surfaces by dipping them in a molten zinc bath (about 450°C). A distinction is made between discontinuous batch galvanizing and continuous strip galvanizing. The latter method is used to produce hot-dip galvanized steel strip, as is the case at Wuppermann.
Why is steel galvanized?
Steel is hot-dip galvanized to protect the component from corrosion (rust). Under normal conditions, the thin zinc layer protects the steel for several decades. Competitive manufacturing costs, durability and largely maintenance-free hot-dip galvanized surfaces make this corrosion protection measure very economical. This also protects precious raw material resources and thus the environment and climate.
How does hot dip galvanizing work?
In continuous hot-dip galvanizing, pre-cleaned steel strip welded end-to-end is continuously passed through a molten zinc bath. In the process, the steel surface is evenly wetted with zinc on both sides. A system of stripping jets directly after the zinc bath ensures a constant layer thickness and a visually homogeneous surface structure. Cooled to ambient temperature and given a preservative surface finish, the galvanized wide strip is finally cut to the desired length, coiled into ring-shaped "coils" and delivered to the customer.
Why is zinc suitable as corrosion protection?
Zinc protects steel very well against corrosion. The so-called passivation layer forms on the surface of the galvanized component as a result of weathering. This is a top layer that protects the component and is worn away by wind and weather over time. However, this layer is constantly renewed by the zinc underneath until it is completely used up. Mechanical damage to the galvanized component (e.g. scratches) also protects it from corrosion. According to the electro-chemical voltage series of the elements, zinc is the "less noble" metal compared to iron or steel and dissolves under certain conditions. It "sacrifices" itself, so to speak, and thus protects the base material steel in the area of damaged areas.
Can hot dip galvanized steel rust?
In most cases, hot-dip galvanized steel only starts to rust after decades of use, but only when the zinc coating has been completely consumed. In general, the thicker the zinc coating of hot-dip galvanized steel, the more corrosion resistant it is, i.e. the longer the steel remains rust-free. The duration of the corrosion protection effect is therefore largely dependent on the thickness of the zinc coating. Another significant influencing factor is the atmospheric ambient conditions to which the component is exposed.