Marine environments are some of the harshest metal parts and components operating conditions. Continuous exposure, elemental forces, and high chloride concentrations contribute to corrosion and component degradation.
Stainless steel can be used to protect against these conditions. This is especially true for grade 316 stainless steel containing chromium, nickel, and molybdenum.
Corrosion Resistance
Stainless steel is known for resisting corrosion in environments where carbon and low alloy metals would quickly degrade. This resistance results from a thin passive layer that covers the steel’s surface, protecting it from electrochemical attack.
Chromium is the main element responsible for this protective effect, and grades of austenitic stainless steel like 304 (also called 18-8 alloy) are the most common marine grades. Other grades, like 316, have added molybdenum, which magnifies this passivity range and makes them more resistant to corrosion from salty water.
Additionally, adding nitrogen in super-austenitic stainless steels reduces the likelihood of pitting and crevice corrosion, making them better suited to coastal services or splash zone applications where chloride can be present in large concentrations. This is why you’ll find stainless steel used extensively in piping and other equipment on vessels of all sizes, from massive freighters sailing the ocean to pontoon boats cruising lake waters.
Structural Integrity
Stainless steel can be used in marine applications that require structural integrity, especially in submerged components like pipes, grills, risers, and equipment attached to the hulls of boats and ships. With highly precise CAD software, engineers can create detailed designs and use laser-fused profiles to make them a reality.
Each type of stainless steel has a limit to the concentrations of chloride it can tolerate, and exposing the material to higher levels will cause it to tea stain. Grades such as 304 and 316, with added nickel and molybdenum, respectively, have a greater resistance to chloride-rich environments.
Docks often have high water levels and harsh chemicals and cleaning products. They also tend to be heavily trafficked by people, animals, and vehicles. Stainless steel offers an excellent solution for these environments because it is resistant to rust, salt, and harsh chemicals and has some natural anti-microbial properties. Stainless steel is, therefore a top choice for dock structures, such as flooring slats, handrails, and decorative drains like those offered by QM Drain.
Durability
Stainless steel is one of the most durable metals. It can be used in marine applications, from large structural supports and catwalks like boat stairs to smaller decorative elements like handrails.
The durability of stainless steel is due in part to its chromium content, which makes it approximately 200 times more corrosion-resistant than steels without chromium. It can also withstand extreme temperatures, which is necessary for marine projects.
Stainless steel is manufactured in various forms, including sheets, plates, bars, and wire. It is also rolled into coils and used in cookware, cutlery, surgical instruments, appliances, vehicles, building construction materials, and industrial equipment.
Recyclability
As a 100% recyclable material, stainless steel is a green raw material. It does not require any chemicals during the manufacturing process and takes a long time to break down into the soil, reducing the amount of waste that goes into landfills.
Stainless steel is used in many defense and domestic applications, from kitchen sinks to knives to cars, airplanes, train engines, and medical scalpels. It is also a primary material in marine environments due to its lightweight, high tensile strength, and corrosion resistance.
In offshore applications, stainless steel can be found in structural supports, catwalks, handrails, and signage. Its versatility and resistance to corrosion in harsh marine environments are crucial. Using high-quality alloys with low nickel content can help reduce the corrosive effects of seawater, including pitting and crevice corrosion. In addition, stainless steel requires less energy to manufacture than other metals. This is important regarding embodied energy, which measures the total energy required to produce a kilogram of metal.
