A correctly selected coating has broad advantages in industrial plants; Coated fixing elements have better resistance to corrosion, prolong their useful life, avoid sudden unscheduled plant stops, increase service applications and reduce downtime due to maintenance or leaks from flanged joints. The main function of the coating on fastening elements is the protection it provides against corrosion, depending on different factors such as: environmental conditions and temperature. For example, studs in an environment with high temperatures and environmental conditions with a high rate of corrosion (such as saline environments), require a coating with better characteristics than fasteners that are used in an indoor environment with controlled environmental conditions.
Benefits of choosing the right coating
The proper selection of the coating for the fastening elements represents a great impact on future maintenance cycles. If the fastening elements are adequately protected against corrosion and friction, periodic maintenance will be facilitated. However, if the fasteners seize due to rust or corrosion buildup, the connection would have to be more difficult to loosen, which means additional work permits, special tools, and additional time and costs. Although loosening studs is often considered a routine part of these maintenance cycles, the associated costs of future delays, labor, permits and tools often outweigh the initial savings of choosing a coating with less protection; “more economical.”
The ideal coating for fastening elements generally has a trade-off between the initial investment of the coating and the reduction in cost overruns due to prolonged maintenance and acquisition of additional equipment.
Blued
Bluing is the most basic coating, where the metal surface is coated with a varnish that prevents the oxidation of the steel, generally black, by means of baths in special paints.
Zinc and Cadmium
Zinc and cadmium are used to add a thin layer of corrosion protection to the fastener through an electrolytic bath. They are low-cost coatings that provide a layer of protection against corrosion suitable for indoor environments, with a controlled climate and low salinity, preventing them from oxidizing during transportation and storage under controlled conditions.
Bichromatized (Irised)
The bichromatic coating (also known as iridescent) provides a layer against corrosion and is made by immersion in zinc and chromium, which has a bright yellow color, generally with a minimum thickness of 10 microns, which provides lubrication and is capable of withstanding a 120hr salt spray test.
Galvanized
The galvanized coating provides resistance to corrosion, impacts and abrasion. It is a coating that is made by immersing the fastening elements in molten zinc at a temperature of 450°C, which allows it to be distributed and cover all of the pieces, obtaining a thickness between 50-100 microns.
Xylan 1424
The coating The application of the coating can benefit the fastener installation process, since by reducing friction and wear, it will increase the useful life. This coating is suitable for applications in places with high salinity, such as near the sea or coastal areas, but should not be used in conditions where the temperature is too high (greater than 176 ° C continuously).
The coatings with Xylan 1424 are applied at the Flexilatina facilities in Colombia and are certified and endorsed by PPG Industries to perform coatings on fastening elements nationwide.
The technical staff will provide advice for each type of application, helping to select the ideal coating according to the needs of your production process.