Steel Profiles

Steel products are particularly susceptible to deterioration due to corrosion or may often require elaborate treatment before being used or further processed.

One particularly frequent cause of damage is rust due to seawater, rain, condensation water in the means of transport, cargo sweat or condensation inside the packaging. Unsuitable means of transport, ships with poor hatch covers or without ventilation facilities, damaged containers, uncovered railroad freight cars and trucks, incorrect storage in the open, use of unsuitable tarpaulins, exposed loading in wet weather conditions, and variations in temperature and climatic conditions during long voyages may result in rust damage.

If a solid bond (adhesion) between concrete and reinforcement steel is to be achieved, relatively clean steel from which loose rust has been removed should be used, i.e. slight surface rust may even be advantageous. Care must, however, be taken to ensure that the diameter of the concrete reinforcement steel still fulfills the requirements of the statics calculations once it has been pickled or sandblasted. Prestressed concrete reinforcement steel, in contrast, must be rejected if it exhibits even the slightest corrosion.

The oxidation layer (scale) which is formed on the surface of steel during hot-rolling or annealing provides limited corrosion protection. This layer does, however, complicate application of anti-rust coatings or galvanization.

Some special, large and angle profiles have a hot-dip galvanized or zinc sprayed finish and are thus protected from corrosion.