How are good wine and Corten steel similar? Simply that both, with the passage of time, highlight their attributes. Time is the best ally of these two. But to start talking about the benefits of Corten steel, it is important to briefly explain a little more about this metal.
Corten steel has its origins in maritime applications, and for its characteristic beauty has been gaining popularity in the architectural sector. It is a common metal, which is not affected by corrosion because it is an alloy of steel, nickel, chromium, copper and phosphorus that after a wetting and drying process that can occur naturally by exposing this metal to the environment or a chemical process in a laboratory to advance this process, the metal develops a thin layer of oxide in a very particular tone between dark reddish and terracotta.
It is important to clarify that in most carbon steels, the rust develops to the point before total decomposition can occur since the oxide layer in most steels is porous and allows moisture and oxygen to continue to corrode the surface. In the case of Corten Steel, these are high strength steels that develop dense adherent oxide films that slow the rate of corrosion as well as copper and aluminum oxides.
Hotel Ritz Carlton Zadun Reserve Cabo, Abax Architects. Panels by Astyl in Corten Steel, Perforart Perforated, Lasion technology.
Evolution of Corten steel; how do you get to that ideal reddish-terracotta rust color?
This steel is distinguished by the color of the oxide that covers it, but it originally comes in silver color and with the exposure to the environment it naturally acquires this protective film. When the oxidation process begins, the layer that develops on the surface starts with a bluish black color and as humidity and slight condensation accumulates, reddish streaks are formed. As time passes and the exposure of the metal to the environment increases, this exposure leads to a thick thin layer of oxide that eventually covers the entire surface of the metal.
Source: Google Images
Cautions/care to be taken into account
Although this product does not require maintenance of any kind, it is important to consider that it is in constant oxidation and therefore it is necessary to contemplate that the runoff of the oxide film quickly stains adjacent materials such as concrete coatings and sidewalks under the steel installations. Whenever it is decided to work with this material it is necessary to design solutions for future runoff, so it is necessary to design gutters or other solutions to avoid staining, among other issues.
Hotel Ritz Carlton Zadun Reserve Cabo, Abax Architects. Panels by Astyl in Corten Steel, Perforart Perforated, Lasion technology.
The relevance of the geographical area and the use of cor-ten steel
The environmental conditions surrounding the Corten Steel project will determine how long it will naturally take for Corten Steel to acquire its characteristic and prized rust finish; that is to say, if the project is installed in the center of a city where there is no contact with high amounts of humidity or dry environment it is possible that the steel will take longer to acquire this oxidized film since the environmental conditions are not optimal for natural oxidation, in these cases it is possible to advance the oxidation process in a chemical way in the plant/laboratory where the panel is manufactured so that the product is ready to be installed with the characteristic finish. On the other hand, if the project where the product will be exposed is a coastal area where the humidity level is higher due to the proximity to the sea, the environmental factors are favorable and help the natural oxidation process to be faster and as time goes by the product will continue to look beautiful.
It all depends on the project, there are projects that require immediately that the product is installed with this finish or there are others that can wait for the metal to react naturally, whatever the case, rest assured that it is possible to manipulate the metal to accelerate or not this natural process and with the passage of time and exposure to the environment the metal will look more and more radiant.
Image: Corten Steel Panel by Astyl
Cost-effectiveness of Corten steel in current projects
When choosing a metal or product in general for finishing, it is important to evaluate the cost per square meter but also not to forget the costs and implications of installation and maintenance. Although Corten steel is a metal with a somewhat high commercial value compared to wood, aluminum, ceramic composites, among others, it offers the advantage of not needing maintenance since Corten steel thanks to its properties, as time goes by, it becomes more beautiful with its reddish-terracotta covering which does not require any additional maintenance or finishing, which translates into profitability and let’s remember that this metal can be recycled, so at the time it is decided to remove the product from the building for any future remodeling, the material still has value and can be recycled to create new metal. Corten steel reminds us of the beauty of aging, it becomes an ode to the passage of time and the beauty of the changes in it.
Author: Mónica Pacheco Abbud
