Corrosion resistant coatings are engineered to protect metal components from degradation, harsh environmental factors, and the strains of high-stress applications. Because the types of corrosion are vast, corrosion resistant coatings must be specifically manufactured to counter chemical reactions between different metals and water, air, and salt. Sometimes a metal alloy’s impurity can lead to its own failure, and corrosion resistant coatings must also work to neutralize the metal’s unbalanced composition. One such corrosion resistant coating is a nickel-chromium alloy, which works well with steel, copper, brass, and zinc substrates. A thin layer, applied using electroplating, can not only change the aesthetic appearance but increase the lifespan of the part by countering corrosive agents and their damaging results.

How Nickel-Chromium is Made The primary element in a nickel-chrome coating is nickel—this is the component that gives the coating its thickness. Chromium, on the other hand, only accounts for around 2 percent of the coating composition. Nickel is also responsible for numerous properties associated with the coating, such as hardness and resistance to corrosion. Originally, chromium was used simply to protect and coat nickel, but it also increases the coating’s overall corrosion resistance, thereby providing increased protection to the substrate. It’s important to understand that there are several different kinds of chromium, not all of which are suitable for use in a nickel-chromium coating. There are three forms of chromium: metal, trivalent, and hexavalent chromium. Metal chromium is a component in stainless steel, and also in chromium plated articles. Trivalent chromium is used for tanning leather, and is therefore unrelated to nickel-chromium coatings or plating. Hexavalent chromium is toxic and contains carcinogens, so it’s often converted into trivalent or metal chromium so it can be used in industrial applications.

Corrosion Resistant Nickel-Chromium Nickel-chromium as a corrosion resistant coating is not a new development. Since chromium plating began in 1926, it has been relied upon for its strength and hardness. When used to coat certain metals, the substrate can withstand environments it wouldn’t otherwise be able to tolerate, such as extreme exposure to rain, salt water, and snow. Steel, which usually rusts when confronted by these elements, retains its strength and finish when coated with nickel-chromium. Nickel-chromium is also extraordinarily abrasion resistant, a trait that makes it useful in the automotive industry where it’s used to coat components that encounter everything from dry road debris, such as sand, to ice and snow. Items that are exposed to constant contact, like railings, facet tap handles, and door handles, also benefit from the abrasion resistant coating as it enables them to not only withstand daily use, but also retain their polished-looking finish. The overall hardness of nickel-chromium also means it’s able to take a fair amount of aggressive cleaning without being compromised. As a result, medical instruments and household kitchenware are able to fulfill their purpose and still resist corrosion. Additionally, nickel-chromium coatings are highly heat resistant, which means they can be sterilized using heat-related methods and used on components that operate at high temperatures. It is also possible to custom design a coating to achieve different levels of corrosion resistance and different finishing styles. For simpler applications, where minimal corrosion resistance is required, the coating specifications can be tailored so as to provide the right balance of chromium and nickel. Deciding ahead of time exactly what purpose the coating will serve will make selecting the appropriate amounts of each coating component easier and more efficient. Additionally, picking out certain aesthetic qualities ahead of time will also ensure that the coating has the desired visual effect when applied to the substrate.