Corten steel: here advantages and applications of a material that for aesthetic features and capabilities is becoming increasingly appreciated and used.
In 1933 the United States Steel Corporation (USS) patents for the first time the Corten steel, today one of the most important materials among the types of low-alloy content (originally 0.2-0.5% copper, 0.5-1.5% chromium and 0.1-0.2% phosphorus) and high mechanical strength. The name “Cor-Ten” comes, in fact, by two English words that define the main features: “Cor-rosion resistance” and “Ten-sile strength”, ie high resistance to corrosion and mechanical resistance.
The real work research on this material, however, is developed from the ’60s: the renowned architect Eero Saarinen employed for the first time the corten in an architectural context, with the creation of the John Deere World Headquarters in Illinois in 1964.
Thus began the history of corten metal that today, for its ability to combine functionality and aesthetics, is widely used in many industries, from construction to road network up to the decorative contexts.
The great success of corten steel is due certainly to its “self-protection” capabilities. This metal, in fact, during the oxidation process, it covers itself of a coating composed of:
This coating, in normal environmental conditions, will form in about 18-36 months and its color varies from an initial orange to a brownish-reddish color. It is what is commonly called “rust” but that for the Corten right for its color characteristics (joined to the functional ones), is protective and lends itself to the most various design solutions. Not only that if this coating is scratched, the oxidation process starts to build a new protection. This is why the Corten is a material which “lives and protects itself”.
In order to form the patina, properly, there are some key factors including:
The advantages deriving from this unique feature are countless. The corten metal, in fact:
The Corten steel is divided into three types which differ in their chemical composition and their thickness and consequently also for the type of application.
Corten steel A
This type of Corten is also called “phosphor” and has the following “structural” features:
Features |
Corrosion resistance (compared to common carbon steels) |
Available thickness |
Applications |
Corrosion stops after having caused a decrease of approximately 0.05 mm thick | 8 times higher |
Up to 12.5 mm |
architectural |
Corten steel B
It is the so-called Corten “vanadium”:
Features |
Corrosion resistance (compared to common carbon steels) |
Available thickness |
Applications |
The high mechanical characteristics of the material are retained even in large thicknesses | 4 times higher |
Up to 100 mm |
Buildings subjected to severe stress |
Corten steel C
Features |
Corrosion resistance (compared to common carbon steels) |
Available thickness |
Applications |
Recently introduced on the market, it has a significantly higher mechanical strength than the steels of type A and B. | 4 times higher |
Up to 25.5 mm (with the exception of the sections in which thickness is 19 mm max) |
Buildings subjected to severe stress
|
In recent years the diffusion of Corten steel has considerably increased and this has led to the introduction of many imitations of this material on the market. Generally, the processes by which one tries to reproduce the corten effect may be divided into three types:
The contexts in which the corten can be applied are many:
An interesting example in this regard, is the work of Cuadra in the project “Brisighella Nuova 2.0 – Comunità Ospitale “: the aim is to create an urban space that can improve the lives of citizens and to enhance, in smart perspective, all the excellence of the small town in the province of Ravenna.
The metal corten flower pot holders signed Cuadra, in fact, have been placed in Piazza Marconi, the main square of the Brisighella village, and integrate with the surrounding space and tying favoring the balance between aesthetics, functionality and architecture. Every centimeter of the square thus acquires its value and becomes green “living.”
To discover the project see “Cuadra’s corten steel planters in Brisighella: a green space to be thoroughly enjoyed”
An interesting example is the realization of Cuadra to the Port of Numana (AN): a project of landscape that is not only creating a new urban space, but use the same harmonic and functional terms. The studied composition includes a series of corten steel elements that decorate the quay of the port and at the same time integrate harmoniously with the surrounding open space: benches, litter bins, bollards and flower pot holders made of corten.
A realization that makes the beauty into the starting point for a larger project to rethink the port area in terms of efficiency: it means to live the city thinking about a space that persists over time, respecting the environmental rhythms.
Here is the project: “The Port of Numana: flower boxes made from Cuadra’s Corten steel … throw the anchor!”
Another relevant example is the project carried through the streets of Riccione: here Cuadra, in collaboration with the architects Angela Magionami and Paola Tassetti, proposed a project based on a strong piece of his collection “Landscape Furniture”: the Tangreen, a modular system assembled and which allows the composition of endless “islands” from a single square module (2x2m) that can be decomposed and assembled in different configurations.
A versatile design, which can mutate and become continuously with the change in rules of shadows, light and that well lends itself to represent the style and the rhythm of the city of Ravenna, in an innovative way in terms of composition and social.
Read more: “With Cuadra the streets of Riccione play at tangram”