Corten is a structural steel grade which is also known as a weathering steel because it forms a protective layer of rust when exposed to atmospheric elements. It is found in a variety of industrial applications including bridge structures and steel framework. And yet in recent years it has become the aesthetic material focus for modern sculpture and is commonly used by leading artists and architects.
The reason for this popularity is quite simple. Corten is a structural grade steel so has good yield and tensile strength. It has good weldability and forming characteristics too Corten. But the main reason for its growing appeal in the art and architectural world is due to its natural rustic appearance.
As the surface level of the steel reacts with elements in the atmosphere, the material forms its own protective layer of rust which is almost orange like in appearance. It doesn’t need painting or treating in anyway, the steel is for all intent and purposes ‘self healing’. The only exception to this is when the material is submerged under water, in which case the outer surface will require treatment of some kind.
It is little wonder then that this steel which requires little maintenance and is interesting and pleasing in colour to the eye, has become such a popular material the new generation of artists, sculptors and architects.
You may not have noticed it, but corten steel is popping up everywhere. A famous example is a sculpture in the North of England called the ‘Angel of the North’ – standing over 20 metres tall and with a wing span of 54 metres across, the sculpture which is located on a hill just outside Gateshead and next to the busyA1 road, welcomes new visitors to the area.
Use of of Corten in coastal areas is not recommended because the salt in the air could de-stabilise the protective layer, meaning that the steel will continue to corrode. It is also difficult to ensure that weld joints weather at the same rate as the material itself. Thinner material which is unprotected could ‘rust through’ over time, though this is not an issue for thicker structural sections.
As the steel is used primarily in its natural condition, performance cannot reasonably be warranted. The onus is very much placed on the purchaser with regards to the suitability of the material for its intended purpose.