There is a misconception about stainless steel in that it doesn’t rust or corrode when exposed to water, specifically sea water. Stainless steel can in fact rust and corrode if continuously exposed over time. However, there are different grades and alloy compositions of stainless steel that make some stainless products more corrosion resistant than others. Grades that are higher in chromium are better suited for wet environments, such as construction projects placed in or near salt water. Stainless steel is a far better material choice than carbon steel or aluminum for these applications.
Corrosion Resistant Grades and Alloys
Marine environments, where the steel is exposed to salt water and sun require special types of stainless steel. The most appropriate stainless steel shapes and profiles are made using the following designations of stainless:
– 304/L Stainless Steel
304/L grade of stainless steel is one of the more popular grades for making components that will hold up well when exposed to salt water but not submerged in it. It is an austenitic alloy that includes chromium and nickel and is lower in carbon than the standard 304 grade of stainless. Laser fused, wide flange, 304L stainless steel beams have been used as a corrosion resistant building material in theme parks where marine animals are the center attraction, requiring salt water tanks and pools.
– 316/L Stainless Steel
Another popular material for marine environments is grade 316/L stainless steel. This is also a lower carbon, austenitic alloy containing chromium and nickel. The addition of molybdenum provides an increased level of corrosion resistance than 304/L. Laser fused c-channels, made from 316/L stainless steel, were used to make the manatee gates that protect this endangered species in Florida’s waterways where salt water meets fresh water. This alloy was also the best choice laser fused beams used for Epcot’s Caribbean Coral Reef Aquarium.
– Duplex Stainless Steel
Duplex stainless steel is a combination of ferritic and austenitic grades of steel. This combination creates steel that is resistant to localized corrosion, such as pitting, stress corrosion cracking, and crevice attack. Duplex steel products have higher strength than other stainless compositions. 2205 duplex stainless steel has been successfully used in the production of marine cranes for lowering and raising boats in and out of salt water. 2507 duplex stainless steel is the next generation and considered a super duplex for similar applications. It has been successfully used in the construction of off shore oil rigs.
Finding the Right Match for Your Salt Water Project
When you decide that stainless steel is the best choice for your marine project, due to its corrosion resistance, durability, and easy maintenance, allow our team to assist you in choosing the most suitable grades and alloys. Stainless Structurals manufactures a wide array of standard and custom shapes and profiles in numerous grades and alloys. Some of these include beams, channels, angles, tees, and hollow sections. Our laser fusion technology is state-of-the-art and will give your project a distinctively clean appearance with precise lines. Please contact Stainless Structurals USA for more information about our domestic manufacturing capabilities and our available inventory.