What Causes Industrial Fasteners to Corrode?

The long-term viability of any industrial fabrication job, from assembly to stud welding, depends on the robust quality of the materials used as well as the response to potential threats against the structure’s strength. In harsh environments, corrosion can undermine the structural integrity of metal connectors, studs, and fasteners, compromising their load-bearing capacity. Understanding factors that contribute to corrosion and methods of combatting them mitigates these risks.

Surface Damage

Because stainless steel acquires its resistance to rust via a chromium oxide film, damaging this layer diminishes its corrosion resistance. Wherever surface damage occurs, the risk of pitted corrosion increases, making it vital that weight-bearing fasteners and connectors are regularly evaluated for indicators of damage. When possible, the use of non-metallic fasteners, such as the T-SEP assembly, provides an alternative to potentially corrosive metals.

Salts

The presence of salt, whether in the form of sea salt, salt found in ocean air, or de-icing salts, significantly increases the opportunity for corrosion. As an electrolyte, sodium chloride contributes to oxidation, causing rust to rapidly develop on vulnerable metals. In the case of stainless steel, this might occur at a point of damage or in a crevice where two materials are joined.

Ions

A variety of ions exist in seawater, any of which can become factors in corrosion by increasing the electrical conductivity of the water. This increase enhances electrolytes, escalating the rate of corrosion.

Sulfate-reducing Bacteria

Sulfate-reducing bacteria occur in large quantities in marine environments and produce corrosion. As the SRBs deplete sulfate found in seawater, hydrogen sulfide, a highly corrosive agent, is formed.

Chemicals

Many chemicals found in industrial fabrication play a part in corrosion. Preservatives used to treat wood, fire-retardants, and even paints can increase the probability of corrosion.

Solutions

While most of these conditions are unavoidable, there are methods by which the opportunity for corrosion can be reduced. Capitalizing on the T-SEP assembly and other innovative non-metallic fasteners minimize the opportunity for corrosion by reducing the use of vulnerable metals. The T-SEP assembly replaces traditional metal tube separators, which are highly susceptible to crevice corrosion.

Where metal is compulsory, the use of corrosion-resistant, grade 316 stainless steel decreases the likelihood of corrosion. Alloyed with molybdenum, which is not sensitive to oxygen, 316 stands up to highly corrosive settings, in particular chloride-rich marine environments.

For more information on PFSNO’s pioneering problem-solving in the industrial fabrication industry, read more on our website or contact one of our experts.