Lubrizol Corporation : Keep Rust and Corrosion from Crippling Your Productivity – Tribology and Lubrication Technology, October 2011

20 MINUTES WITH…

Derek Phillips

By Thomas T. Astrene / Publisher

Keep rust and corrosion from crippling your productivity by following the advice of this product-development specialist.

Derek Phillips The quick file:

Education

• Associate's of science degree from Ferris State

University, Big Rapids, Mich.

• Bachelor's of science and Master's in business administration from University of Phoenix

Work experience

• The Lubrizol Corp., Wickliffe, Ohio, 1993-Present Several roles supporting industrial additives development globally in project product, business development and commercial management.

• Petro-Lube Inc., Whitmore Lake, Mich., 1989-1993

Development of industrial lubricants, specifically water-based metalworking fluids.

TLT: Please describe the arc that led to your career in tribology and specialization in metal protection.

Phillips: Through most of my career I've focused on industrial and automotive lubricants. My job responsibilities have cov- ered additive formulating, technical service, new technology development and sales support.

I had a great opportunity to work three years in China. I was able to use my collective experiences with industrial fluid technology to start an industrial technical support labo- ratory and to educate our sales force and customers.

Returning to the United States, my career took a logical direction (at least I think so!) toward managing the global commercial activities for Lubrizol's metal-protection addi- tives business. Today I focus on setting product-development

strategies based on my knowledge of end-users' needs and working with others on our industrial team to understand market dynamics. This allows us to assist our customers and to help them to be more successful. What could be more re- warding?

TLT: Many people believe corrosion and rust are the same thing. Describe the difference.

Phillips: Rust is a term used to describe the corrosion of iron and iron alloys. Corrosion is a term that covers the destruc- tion of any metal. In general, corrosion is the deterioration of a metal by oxidation or other chemical action.

Iron can take on many different oxide states, and the most commonly observed iron oxidized state is what we of-

18Did you know? STLE was founded on March 3, 1944, in Chicago as the American Society of Lubrication Engineers (ASLE).

ten describe as red rust. In some instances, oxide layers can be considered beneficial, forming protective films to some metal sub- strates like aluminum. Even passive iron ox- ide layers formed in the bluing or black ox- ide process, traditionally used to protect military equipment, will still require some rust preventive for protection from further corrosion.
Iron parts that have any stain are gener- ally regarded as defective, and corrective ac- tion must be taken. When there is a change in color to an iron surface, you can assume there is some level of corrosion that leads to aesthetic issues and, in the worst possible case, catastrophic mechanical or structural failure.

TLT: What are the biggest dangers that rust and corrosion present to machinery?

Phillips: We can safely say that hidden rust and corrosion on or in a machine will even- tually have a negative impact on an opera- tion's economics. This negative cost impact can be as simple as replacing a part and re- sulting loss of productivity or, more seri- ously, to extensive downtime from a cata- strophic failure if a corroded component goes undetected.

Corrosion inhibitors are needed throughout the lubricant industry for both automotive and industrial applications to protect ferrous and nonferrous moving or freshly machined parts.

ments, the protectant formulation and the protectant's film
All machines are composed of different metal substrates that provide their individual wear, strength, ductility and corrosion characteristics. Having multiple metals in a piece of equipment can cause galvanic corrosion, which creates electrochemical attack. Some metals are more prone to chemical attack than others. These variables must be fully understood by equipment designers and machine operators, so the best metal substrates and appropriate protective chem- istry is employed to minimize risk and meet the desired product lifecycle for each piece of equipment.

TLT: Why can't a rust preventive prevent rust permanently?

Phillips: The ability of a rust preventive to protect the surface varies based on a number of aspects including substrate type, surface finish, surface preparation and environment. These factors are then applied in formulating the right adhesion and film characteristic.

Rust preventives are formulated for a specific end-use re- quirement and, therefore, vary in protection properties. A manufacturer may only need to protect a part between man- ufacturing processes or between shipping points. In some cases, the part may be protected from the elements found inside a warehouse, but in others it may be exposed to harsh outside conditions including saltwater or acid environment exposure. Again, depending on the performance require-
thickness will vary.
Applying the rust preventive is a critical part of the over- all performance. Parts or equipment are commonly brushed, dipped or sprayed with the rust preventive. Dirty parts or equipment create poor contact for the rust preventive film, reducing effectiveness. A clean metal substrate provides bet- ter adhesion and consistency of the protective barrier. Like- wise having a wet part from the MWF, cleaner or rinse water requires the rust preventive to displace and shed the con- taminant from the surface. Additionally, once the water is displaced, the rust preventive should separate the water, minimizing re-contamination of the metal substrate and al- lowing the fluid to be continually used.
The final film may be oily, waxy or greasy depending on the protectant requirement and subsequent processing. Oil- based products generally wash off easier. This may be good if the part is to undergo further processing, but protection is usually reduced.
Waxy or greasy films are more tenacious, making them by and large harder to remove, but provide a more resilient pro- tective barrier. Overall these protective films are not perma- nent and are removed if a further permanent finish is ap- plied.
Solvent degreasing, once a common practice, has been re- placed with alkaline wash solutions and minimal abrasive cleaning. This is where a full understanding of the customer's
WWW .S TLE. OR G TRIB OL OG Y & L UBRIC A TION TE CHNOL OG Y OC T OBER 2 011 • 19

'Rust preventives are commonly used to protect freshly prepared metal substrates.'

performance needs must be understood to provide the best solution.
While in service, contaminants and abrasion can break through the barrier reaching the metal substrate and poten- tially starting the corrosion process. To prolong the longevity of service, formulators use a combination of film formers and chemical passivators. Film formers help resist physical breakdown, and chemical passivators protect from water and acidic environments that can make it through to the surface. One can see the challenge of formulating a rust preventive that provides the maximum protection for a given substrate and operational environment.

TLT: What is the difference between corrosion inhibitors and rust preventives? What are the appropriate applications for each?

Phillips: The classification and use of these terms are often loosely interpreted. Generally speaking, corrosion inhibitors protect metal surfaces while the fluid is in contact with a surface or within a specific process. Rust preventives are used to protect freshly processed metal surfaces.

Corrosion inhibitors are needed throughout the lubricant industry for both automotive and industrial applications to protect ferrous and nonferrous moving or freshly machined parts. Corrosion inhibitors are formulated into lubricating oils to protect metal surfaces from common contaminants such as acidic oxidation byproducts and condensed water. Active chemical components necessary to provide the tribo- logical properties for some metal surfaces can be corrosive to
other substrates. Corrosion inhibitors are for- mulated to protect these parts.
Additionally, many chemistries used for other primary functions such as detergency, emulsification and antiwear properties can prevent corrosion or rust
from forming. These multifunctional chemistries require careful formulation balance to provide the necessary perfor- mance properties.
Rust preventives, on the other hand, are commonly used to protect freshly prepared metal substrates. These products are formulated to provide blemish-free surfaces from a wide range of conditions that generally are removed later in a fur- ther process or finishing step.
Rust preventives are required in a number of end-user ap- plications ranging from protecting freshly rolled metal in a steel mill to protecting finely ground ball bearings manufac- tured domestically or internationally to be shipped and stored around the globe. Developing a rust preventive for a specific application requires formulating techniques that take into account water displacement and water separation while building in the proper physical and chemical charac- teristics desired for the length of protection and the antici- pated corrosive environment.

TLT: What are the respective pros and cons of solvent- and water-based rust preventives?

Phillips: Solvent-based rust preventives make up the greatest percentage of the rust preventive market as they have been in use the longest and because of certain performance attributes including fast drying times, film consistency, wetting proper- ties, water displacing and separating capabilities.

But solvent-based protectants are facing environmental and regulatory challenges with new VOC (volatile organic compound) regulation requirements and safety issues sur- rounding shipment of materials with low flash points. Some suppliers have looked to solvents and oils with higher flash points, but there are tradeoffs as the film type can change and may not be compatible with end-user requirements.
Water-based rust preventives allow end-users to have a safer and often cleaner work environment while still provid- ing as much protection as solvent-based rust preventives. Water-based rust preventives can be formulated so the result- ing film is dry to touch or oily.
Highly specialized product formulation is required with careful adjustments to concentration levels. The resulting product may exhibit slower drying times depending on tem- perature and humidity of the environment. Both solvent- and water-based rust preventives can be formulated to meet the desired corrosion performance needed by end-users around the world.

TLT: What do end-users need to know before changing to water-based rust preventives? What about switching penalties?

Phillips: Water-based rust preventives may require more

20 • OC T OBER 2 011 TRIB OL OG Y & L UBRIC A TION TE CHNOL OG Y WWW .S TLE. OR G
training and support for end-users whose operators are more familiar with solvent- or oil-based rust preventives. Getting the right amount of protective film for customers' applica- tions may require some dialing in of the rust preventive con- centration and application.
For example, if the manufacturer is looking for a dry-to- touch product in just a few minutes after processing, it's pos- sible that forced air drying may be required. Parts that are hot versus ambient after processing may require more or less at- tention to drying. Attention also must be given to concentra- tion maintenance of the protectant due to different evapora- tion rates. Geographic location can present challenges with changing atmospheric conditions and seasonal changes, from rainy monsoon to dryer winter months.
If the end-user has had experience with monitoring and maintaining water-based products in an industrial setting, the switch will be less of a burden as he is familiar with the more challenging operating aspects and will plan according- ly. Managing hard water, evaporative losses and biological activity should be incorporated into operations and become a regular monitoring activity.
All in all, managing water-based rust preventives is more involved, and managing the changes can have a substantial impact on product performance. At the end of the day, man- ufacturers may spend more time managing water-based rust
preventives, but the benefits of a safer work environment and potential final cost savings should be carefully considered.

TLT: If you could offer one piece of advice to a lubrication engineer assigned to solve a corrosion/rust problem, what would it be?

Phillips: Consider the conditions pre- and post-process before making a conclusion or recommendation. The type of con- taminant found in the process or potentially impacting the process or the product need to be fully considered, as they will present specific challenges to the lubricant or rust pre- ventive.

Taking sufficient time to ask and understand the entire requirement, problem or opportunity can provide longer product lifecycles and solve preventable corrosion problems through high-valued lubricants and rust preventives. Don't forget to use the resources you may have from the chemical and engineering disciplines to understand root causes and industry best practices in determining your optimum solu- tion.
Delivering the best possible solution requires a careful combination of process, operational practice, materials and carefully formulated rust preventives or lubricants.
You can reach Derek Phillips at [e-mail]
WWW .S TLE. OR G TRIB OL OG Y & L UBRIC A TION TE CHNOL OG Y OC T OBER 2 011 • 21