Your Fastener Distributor Explains Different Types of Corrosion

Corrosion is the adversary of fasteners everywhere. Understanding the various types of corrosion allows you to choose appropriate fasteners and your fastener distributor is always willing to help in that process. More than just rust and decay, corrosion can quickly result in fastener failure. Even stainless steel fasteners can be subject to certain types of […]

Corrosion is the adversary of fasteners everywhere. Understanding the various types of corrosion allows you to choose appropriate fasteners and your fastener distributor is always willing to help in that process.

More than just rust and decay, corrosion can quickly result in fastener failure. Even stainless steel fasteners can be subject to certain types of corrosion in specific applications. Find out which corrosive reaction pertains to your application and take the steps required to combat it.

Types of Corrosion

• General Corrosion – when the passive film on a fastener breaks down, active halogens move in and corrode the metal. These halogens include iodine, bromine, fluorine and chlorine, as well as others. General corrosion affects the whole surface and tends to create a spongy look on the surface of the fastener.

• Galvanic Corrosion – this type of corrosion occurs when dissimilar metals are used together, producing an electrical current that slowly breaks down the anodic metal. Due to the high salt content in seawater, fasteners used in marine applications often experience galvanic corrosion. Ask your fastener distributor about what metal combinations result in this type of corrosion, and steer clear from the risk.

• Stress Corrosion – stress corrosion often occurs when steel fasteners are exposed to high levels of chloride. This condition leads to cracking when combined with tensile stress, creating dangerous conditions in a wide range of applications.

• Intergranular Corrosion – this type of corrosion occurs in welding applications, where the high levels of heat alter the location of chrome, an important element in corrosion resistance. Low carbon steel is best for welding applications, since this minimizes the risk of intergranular corrosion.

• Crevice Corrosion – areas with limited oxygen, such as under the fastener head or between nut/washer and the bonding surface, cannot re-passivate as quickly as other areas, increasing the risk of corrosion from chloride. This affects both stainless and non-stainless steel fasteners.

Your fastener distributor understands the effects of all the different types of corrosion, and is available to help you choose the right fastener for the job. Create a joint that will withstand corrosion by understanding the causes of this common condition.