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WonderAdaptive materials fact

Weathering steel, often known by the trade name Cor-Ten, is an alloy that forms a tight, stable layer of rust when it is left out in the weather. That layer slows further corrosion, so the steel needs no paint.

United States, 1933

EngineeringArchitectureDesignTechnology

The story behind the card

Ordinary rust flakes off and exposes fresh metal, so corrosion keeps eating inward. Weathering steels contain small amounts of copper, chromium, nickel and phosphorus, which help the rust form a dense layer, called a patina, that sticks to the surface and keeps out much of the oxygen and moisture. Its colour darkens from orange to deep brown over a few years. US Steel introduced the alloy in 1933 for railway wagons carrying coal and ore. It only works where the surface can dry out between wettings; constant damp, sea salt or water trapped in joints defeats it. The first building to leave it bare was the John Deere headquarters in Moline, Illinois, designed by Eero Saarinen and completed in 1964.

Türkçe oku
Corten çelik, açık havada kaldığında yüzeyinde sıkı ve kalıcı bir pas tabakası oluşturan bir alaşımdır. Bu tabaka paslanmanın ilerlemesini yavaşlatır; bu yüzden çeliği boyamaya gerek kalmaz.
ABD, 1933

Sıradan pas pul pul dökülür ve altındaki taze metali açığa çıkarır; böylece paslanma içeri doğru ilerler. Corten gibi hava koşullarına dayanıklı çeliklerde az miktarda bakır, krom, nikel ve fosfor bulunur. Bunlar pasın yüzeye sıkıca yapışan, patina denen yoğun bir tabaka oluşturmasına yardım eder; bu tabaka oksijenin ve nemin büyük kısmını dışarıda tutar. Rengi birkaç yıl içinde turuncudan koyu kahverengiye döner. US Steel alaşımı 1933'te kömür ve cevher taşıyan yük vagonları için piyasaya sürdü. Koruma ancak yüzey ıslandıktan sonra kuruyabiliyorsa işe yarar; sürekli nem, deniz tuzu ya da birleşim yerlerinde biriken su patinayı bozar. Bu çeliği çıplak bırakan ilk bina, Eero Saarinen'in tasarladığı ve 1964'te tamamlanan, Illinois eyaletinin Moline kentindeki John Deere genel merkezidir.

Sources and further reading

Background reading: Weathering steel
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