Weathering Steel, also referred to as Corten steel, was first developed in the 1930s as a rust resistant steel alloy for use in architecture and infrastructure construction projects. Developed in 1933 in France, the steel alloy has significantly higher content of copper, chromium, and nickel which forms a stable rust-like oxidation layer on its surface when exposed to weather. This patina protects the bulk of the underlying steel from further corrosion.
The steel alloy gained popularity in construction during the 1950-60s period when many large infrastructure projects utilized its beneficial properties. Some of the early iconic uses of Corten steel structures include the Trylon and Perisphere at the New York World’s Fair of 1939 and the Lustron homes of the 1940s. However, its use soon declined due to concerns over the aesthetics of its rust-like appearance. It re-emerged in prominence in the 1970s, driven by the need to reduce maintenance and finding economical material alternatives for large projects.
Usage in Infrastructure Projects Boosts Demand
Corten steel has proven highly useful for bridges, ports, and other infrastructure which require durable, low maintenance materials that can withstand harsh weather environments. Its natural rust layer protects the underlying steel and eliminates the need for costlier painting and re-coating required by ordinary carbon steels. This significantly reduces total ownership costs over the multi-decade lifespans of large infrastructure assets.
In the last few decades, billions of dollars worth of bridges, oil rigs, ports, and industrial facilities across the globe have utilized Corten steel. Its non-reflective appearance has also made it preferable to ordinary steel for aesthetic reasons. Some notable uses include the approaches to the Golden Gate Bridge, the port facilities at Antwerp in Belgium, and large liquefied natural gas (LNG) tank farms worldwide.
An increasing number of developing countries are also now opting for Weathering Steel due to its economical total cost of ownership. Projects in China, India, Brazil, and parts of Africa have significantly increased construction demand. However, supply chain constraints and limited domestic manufacturing capacity remain challenges, especially as projects scale up in size and number.
Changing Perceptions and Design Advantages
While its rust-like appearance was initially considered unsuitable for architectural applications, today Weathering Steel is increasingly being specified for iconic buildings and structures. Designers have come to appreciate its naturally evolved patinas as adding unique character and texture to projects. Notable examples utilizing Corten steel include the Kielder Water Dam in England and the Statue of Liberty renovations completed in the 1980s.
The material also offers advantages from an engineering and design standpoint. Its low maintenance and inherent corrosion resistance reduces long term capital expenditures.The natural patinas form a protective oxide layer without the need for painting, sandblasting or other refinishing. This eliminates the usage of harmful chemicals and lowers carbon footprint of material maintenance over the operational life of the structure.
Weathering Steel is now easier to procure with multiple global suppliers able to provide alloys conforming to standards like ASTM A588. Custom alloying allows tuning mechanical properties as required. Fabricators have also gained experience working with the material, addressing concerns around welding and erection that slowed earlier adoption. BIM modeling helps architects and engineers visualize how the steel will weather over long periods.
Growth Opportunities in Marine Applications
The corrosion resistant properties of Corten steel make it highly suitable for offshore and marine environments that accelerate ordinary steel degradation. This opens up new growth prospects in sectors like shipbuilding, offshore oil rigs and LNG tankers. The material allows simplified maintenance procedures and extended asset life even under harshest conditions like saltwater immersion.
Shipbuilders across Asia and Europe have started incorporating Corten steel more widely in vessel architectures. The hybrid RoPax ferry Viking Grace operating in Baltic Sea waters between Finland and Sweden utilizes maximum Corten steel content of any passenger ship. Oil tankers, LNG transport ships and offshore platforms are increasingly outfitted with the alloy. This is expected to drive several hundred million dollars of new demand over the coming years.
At the same time, tighter environmental regulations are necessitating moves to low maintenance steel alternatives. Weathering Steel helps ship owners comply with recycling and reuse mandates through its ease of disassembly at end of operations. As maritime infrastructure expands globally to support energy and trade growth, widespread deployment of Corten steel can significantly lower overall carbon footprint through reduced maintenance needs.
Addressing Supply Chain Bottlenecks
With its diversifying use cases and advantages becoming well established, annual global demand for Corten steel exceeds 20 million tons currently. However, downstream bottlenecks remain a constraint amid growing requirements from megaprojects and shipping sectors. Most manufacturing capacity remains concentrated within few suppliers in developed like North America and Europe.
Developing Asian and African countries spearheading huge infrastructure spending lack sufficient local supply sources. This necessitates expensive imports adding costs. Limited availability also affects project timelines. Strategic capacity expansions by global mills and nurturing of regional mini-mills could help address this mismatch. Governments are increasingly collaborating to incentivize Corten steel production facilities that create local jobs and manufacturing capabilities.
Coastal special economic zones promoting shipbuilding and engineering are ideal sites for such investments. Advances in smelting and metal forming technologies may also help eliminate energy intensive processes, further lowering Weathering Steel costs to aid its adoption. As construction material demands balloon to support worldwide development goals, bolstering resilient supply chains for sustainable options like Corten steel will remain a priority.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
