Corrosion Resistance

Whitford coatings provide excellent corrosion resistance for metallic components in hostile environments; improving component performance and longevity whilst reducing downtime, maintenance and associated costs. In addition, Whitford’s Xylan® coating range protects against abrasion and act as dry lubricants; ideal for fail-safe applications such as storm valves.

Corrosion is a key concern in many industries where components are exposed to harsh environments as damage can be costly.

Types of corrosion

Chemical corrosion:

The gradual destruction of a metal surface due to reactions taking place between the surface and its external environment: whenever a gas or liquid chemically attacks an exposed surface. Chemical reactions occur, mainly oxidization, accelerated by warm temperatures, acids and salts.

Crevice corrosion:

Occurs in confined spaces such as gaps and contact areas between parts, under gaskets or seals, inside cracks and seams, etc.

Crevices of sufficient width to permit entry of the corrodent, but narrow enough to ensure that the corrodent remains stagnant, encourage corrosion.

Galvanic corrosion (Bimetallic corrosion):

An electrochemical process in which one metal corrodes preferentially to another when both metals are in electrical contact and immersed in an electrolyte. The less resistant metal becomes anodic, the more resistant metal cathodic. Galvanic corrosion typically occurs when stainless-steel fasteners are used with ductile iron. Xylan coatings have a dielectric strength from 500-1200 volts per mil, which inhibits galvanic corrosion.

Pitting corrosion:

Formed when a small hole or cavity occurs on a metal surface. Often small in size, these holes can be difficult to detect yet are one of the most destructive forms of corrosion. Localized corrosion, pitting is confined to a small area and often gives the impression of a rough surface.

Xylan coatings improve corrosion resistance in three ways:

  1. Inhibition: The use of select pigments inhibits the corrosion reaction and promotes the formation of a stable, passive oxide layer on the metal surface
  2. Sacrificial protection: Primers highly filled with anodic metallic pigments corrode more readily than the base metal – the by-product of sacrificial corrosion fills the pores within the coating, reducing the corrosion process
  3. Use of inert fillers: Increase the length of the diffusion path of the necessary components of corrosion – providing a barrier to oxygen and moisture, the corrosion reaction is greatly reduced

Whitford’s corrosion resistant coatings have benefits for and are sold into various markets:

Click here for our coatings

Click here to contact us