Stainless Steel, as its name implies, is best known for its corrosion resistance properties. But the many benefits and revolutionary uses of stainless steel extend far beyond any single attribute, as attested by its presence in applications in nearly every industry. Of course, one of the most visually stunning and transformative implementations of stainless steel has been within the field of architecture, which has altered skylines around the world.
But while stainless steel is prominently featured in iconic structures and buildings that are instantly recognizable, it is just as important to small-scale architecture, such as homes, offices, and city infrastructure. These examples may not be as famous, but their impact on our everyday lives is every bit as important.
What Properties of Stainless Steel Make it Indispensable to Modern Architecture?
Architecture has high requirements when it comes to material selection. Architects need metals that are strong, durable, and lightweight, but which will also be cost effective. Structural components, especially those in which safety will be a key consideration, must be able to withstand extreme weather, climate, air pollution, and earthquakes. Not to mention, the materials must be flexible enough to fit many different use scenarios while having an aesthetic appeal, even after much time has elapsed.
Stainless steel offers all of the above and more.
The most well-known benefit of stainless steel is obviously its corrosion resistance. While every alloy offers significant improvements over standard carbon steel, certain alloys provide protection against the most extreme marine and acidic environments. As a general rule, the lower alloy grades offer corrosion resistance for normal atmospheric environments. The higher grades, for instance, those with molybdenum added, are resistant to acid and alkaline exposure, chlorides, and more, making stainless steel indispensable for structures such as refineries, power plants, and seawater installations.
At the same time, stainless steel has a high tensile strength with exceptional fatigue properties. Different alloys are better suited for different scenarios. For instance, austenitic stainless steels can be hardened with cold working, while duplex stainless steels have reduced thickness. Many alloys also feature extreme toughness, able to withstand elevated temperatures all the way to below freezing.
Other benefits of stainless steel include heat resistance, ease of fabrication, and ease of cleaning. Its bright, silvery surfaces give this material an attractive, modern appearance, while also offering long-term protection. Moreover, it requires less maintenance than many other metals, providing architects and building owners long-term value.
What Alloys are Particularly Common in Architecture?
Stainless steel comes in five distinct families of alloys, each of which offers particular benefits. The different grades are generally categorized based on their alloying elements, which are what determine the chemical structure and mechanical properties.
The austenitic family is the 300 series of alloys, and they contain a mix of chromium, nickel, and molybdenum, and are non-magnetic. The ferritic family is contained within the 400 series of alloys, characterized by at least 10.5% chromium and low carbon presence. The martensitic family is also among the 400 series alloys, and they generally contain more chromium and carbon ferritic alloys. Duplex alloys are a combination of austenitic and ferritic grades in roughly equal proportions. Finally, precipitation hardening stainless steels have both chromium and nickel added and are a combination of martensitic and austenitic grades.
The most common alloys found in architectural applications are from the austenitic family. As they account for more than 70% of all stainless-steel production, this is not a surprise. The most common alloys are 301, a lower alloy grade that offers high strength and ductility, 304, a general purpose grade and the most common stainless steel on the market, and 316, which has superior corrosion resistance and is thus found in many marine applications. The most common alloy outside of the austenitic family is grade 430, which is primarily found in interior architectural applications.
More recently, specialty alloys are becoming more prominent. While often more expensive, these advanced metals offer superior performance and can meet many requirements that more standard grades of stainless steel are unable to. For example, newer molybdenum stainless steels have become sought after, especially in corrosive locations where enhanced corrosion resistance is of paramount importance.
What Architecture Applications Use Stainless Steel?
From its earliest days, stainless steel has been a go-to material for architects. Beginning in the 20’s and 30’s, stainless steel was prominently employed in iconic structures, such as the Savoy Hotel in London and the Chrysler Building in New York City. Its modern aesthetic and sleek appearance became emblematic of the art deco movement. Because of stainless steel’s durability, many of these early buildings still retain their original appearance today.
In modern architecture, there are many examples of how stainless steel has transformed what is possible for designers. Prized for its durability, stainless steel is also prized by architects because of its extreme formability and versatility.
One recent example of stainless steel architecture is the ice hockey stadium at the 2018 Pyeongchang Winter Olympics. The exterior of this instant landmark was covered in lean duplex stainless steel. Because of the stadium’s location only seven kilometers from the coast, the exterior needed a high level of corrosion resistance. Lean Duplex 329LD Steel was used, for its high strength and corrosion resistance, as well as its cost-effectiveness.
To get an idea of the tremendous versatility of stainless steel, the new compound for Sumatran Tigers at the London Zoo was built from woven 316 stainless steel mesh. The roof of the 2500 square meter enclosure needed to be transparent in order to allow visitor viewing from every angle. The final solution combines high strength with lightweight in a structure that will endure for decades.
At Clinton Aluminum and Stainless Steel, our belief is that every manufacturer should have the right alloy for the job. Our knowledgeable and professional staff takes pride in being more than just a materials provider. Our goal is to be a partner to every one of our customers. Contact us today to discuss what alloy is right for you.