The key to preventing metal corrosion is to stop or slow the electrochemical forces that cause corrosion. Some metals are much more at-risk for corrosion than others. One of the main corrosion prevention factors is to choose a metal base that’s a low corrosion risk given its intended application and the environment it’s used in.
It’s also crucial to assess which corrosion causes a product may endure in order to prevent electrochemical breakdown. Above-ground applications have the highest atmospheric conditions that threaten a product. Generally, the best corrosion prevention is a top coating like paint or a baked-on powder. Below-ground applications also benefit from usable, but they usually need an anti-galvanizing treatment to stop electrical activity.
Metal corrosion may be inevitable given the right time and conditions. However, corrosion and engineering research has discovered short- and medium-term solutions to slow the kinetic process that causes corrosion and put the economic burden onto society. Here are the main types of corrosion prevention methods scientists and engineers work with:
Product Design: Scientists and engineers constantly thrive to improve existing technologies and design new corrosion-resistant metals. This includes developing advanced computer models that simulate actual conditions without the time and expense necessary to test products in real environments. Design work takes in accelerated testing in controlled conditions. Here, newly designed metal alloys provide the least corrosive metals. Plus, testing advanced coatings and finishes provides accurate performance predictions without the need for field tests.
Risk Mitigation: The same product design tools and databases allow metallurgists to mitigate the risk of product failure in real-time situations. Over the years, corrosion risk mitigation came from long-term study and experience of what metal alloys and protective coatings performed with the least corrosive action. Today, risk mitigation starts with applying the right corrosion resistant metals to their performance environment and then matching the correct protection in the way of coatings and electrochemical grounding.
Corrosion Detection: Metal scientists and structural engineers monitor existing products, buildings and infrastructure components to detect corrosion at different stages. Highly-technical sensors and remote monitors provide information on corrosive reactions that simply can’t be found by human sight and touch. Detecting metal corrosion plays a large part in prevention programs. Assessing current corrosion damage detected in existing materials provides a prognosis for predicting degradation and preventing serious failures.
Corrosion Prediction: Research and development, along with detection and mitigation techniques, allow scientific models to predict which metal products will withstand environmental forces. Scientific data also lets designers predict which materials are doomed for failure. Predictions based on metal properties extend into providing an accurate prescription of corrosion-resistant finishes and the successful way they can be applied to protect products. From information-based predictions, better materials and better protective coatings continue to evolve and make the world a safer place.
What Are the Most and Least Corrosive Metals?
True metals are rarely found in the earth’s mineral supply. Most true metals like gold, silver and platinum are non-corrosive by nature. They inherently resist corrosion and are in high demand, which is why they can be so expensive.
Other metals like copper, aluminum and brass also have excellent corrosion resistance properties. These materials are more abundant than precious metals and less costly by volume. The downside to brass, copper and aluminum is that they require considerable amounts of energy to process into usable products. That energy stores in their molecular makeup and makes them vulnerable to nature’s energy recycling program of electrochemical corrosion.
Copper is an interesting metal. It’s in relatively plentiful supply and is easy to work with. However, copper doesn’t need paint or powder coatings to preserve it from corrosion. When exposed to air and water, copper builds its own protection called passivation. Think of America’s famous landmark, the Statue of Liberty. Its copper sheathing has a rich greenish patina that naturally resists corrosion without other help.
Aluminum also forms a passivation protection layer. Without its greyish and mottled patina, shiny raw aluminum is somewhat corrosive. Boat builders often use aluminum for hulls and superstructures, which is partially because aluminum is lightweight and partially because it works well with products called sacrificial anodes. These small zinc or magnesium blocks or anodes absorb corrosive electrochemical reactions from aluminum and self-sacrifice by corroding first.
Because of corrosion threats, even resistant metals like aluminum often receive a surface protection coat. Many aluminum products destined for atmospheric exposure receive treatments during their manufacturing stage. Aluminum building products like siding and gutters have powder coats applied that last through years of harsh weather exposure.
Other metal alloys stand up well against corrosive conditions. Stainless steel is a blend of iron and chromium. As corrosion-resistant as stainless steel is, products manufactured from stainless steel often require protective coatings or regular anti-corrosion maintenance. Here is a list of common metals ranging from the most to least corrosive metals:
Magnesium and Alloys: Either cast or wrought
Zinc and Alloys: Wrought, die-cast or plated
Iron: Wrought, cast or carbon alloys
Steel: Refined iron and alloys like stainless steel
Aluminum: Smelted or cadmium plated
Lead: Solid or plated
Tin: Raw and lead-soldered
Chromium: Used to alloy stainless steel
Brass: Including bronze and alloys
Copper: Solid or plated
Nickel: Including titanium alloys
Silver: Solid or plated
Gold: Solid or plated
Platinum: Including gold-platinum alloys
Best Metals to Use
For most applications, you can use four reliable and economical metals. Each has distinct properties, and your metal choice depends on your specific application. That might be custom sheet metal fabricating, custom enclosure fabrication, steel fabrication or aluminum fabrication. No matter what your purpose, matching the best metal to use always includes providing it with the proper finish, such as powder coating.
Powder coating is an exceptionally dependable corrosion resistance process. This involves energizing a clean metal product and spraying a dry powder over it. The electrostatic reaction allows the powder to stick or adhere to the product. Following this, the metal product enters an over where it’s baked at 400 degrees Fahrenheit. Powder coated metal is one of the most cost-effective and long-lasting metal treatments available today.
APX York Sheet Metal provides first-rate metal fabrication and powder coating. Our services include product design, metal bending, metal rolling, laser cutting, machining, metal shearing and welding. Resisting corrosion is at the top of priorities at APX York Sheet Metal, which is why we always use these four best metals for building corrosion-resistant products:
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