Corrosion Inhibitors

Corrosion is an electro-chemical process that results in the discoloration, pitting, and eventual erosion of a metal surface. Uncontrolled corrosion can result in equipment damage, increased power consumption, unsalable parts, and other economic stresses that can be avoided through the use of proper corrosion preventives.

A corrosion preventive provides chemical inhibition or a physical barrier to the corrosion process. They normally contain a carrier such as, solvent, oil or water. Various polar additives are used form a film on the metal surface. The product may also contain wetting agents, oxidation inhibitors, neutralizers, couplers, and additives that aid with water displacement. Factors in choosing a product include: metal type, desired film type, term of protection, application method, shipping/storage conditions, and subsequent processes and coatings.

The surface's chemistry, reactivity, and complexity are the main factors to consider. Most metals are susceptible to some form of corrosion, particularly if the surface has just been machined or cleaned. This must be addressed by incorporating an inhibitor in the process fluid or applying one immediately after the cleaning operation.

Type of Film
The type of film left by a corrosion preventive can range from a hard, dry coating to a waxy or oily film, to an imperceptible film. The desired film characteristics will be determined by the how the part is handled afterward and the type of packaging or labels that are used.

The term of protection is dictated not only by the initial effectiveness of the preventive, but also by the chemical and physical stability of the film it provides. Additives such as anti-oxidants are used for this reason.

The corrosion preventive can be applied by spray, dip, swab, flow or roller coating. The desired method will help determine the appropriate viscosity, volatility and wetting characteristics of the fluid.

The temperature, humidity and type of atmosphere are critical to the required protection. Even indoor storage can place high demands on the corrosion preventive if an adjacent process produces a corrosive environment. Also, transfer of parts from a cold truck into a warm plant may cause condensation that would tend to wash off a water-based film.

Next Process
Subsequent processes or coatings will often dictate the required compatibility or cleanability of the corrosion preventive. This is especially true if the part will be painted or plated afterward.

Process fluids offers a range of corrosion preventive products. Please review the appropriate product data sheet for specific use recommendations.

Water Dilutable 
6200Synthetic - moderate protection.
6303Synthetic - non borate, moderate protection.
6400Soluble oil - moderate protection.
6600-HDSoluble oil - long term protection.
Solvent Based 
6510Water displacing. Thin waxy film with moderate protection.
6513-DWater displacing. Thin oily film with moderate protection.
Oil Based 
6000Water displacing. Oily film with moderate protection.
6000-LVWater displacing. Low viscosity oily film with moderate protection.

Process fluids also offers an extensive range of cleaners, metalforming lubricants, machining & grinding fluids and quenching fluids. Please consult your local representative for additional information.