Features - May 2013

Beating the Heat — New Anti-Corrosion Coating Aims to Make Metal Alloys More Durable

Wouldn't it be nice to have grill components that lasted longer? NETL research offers some hope.
Wouldn't it be nice to have grill components that lasted longer? NETL research offers some hope.

It's summer and not a cloud in the sky. A perfect day for outside entertaining. Your guests start to arrive including weird Uncle Albert, sports-obsessed Cousin John, and know-it-all Brother David (it's not just my family is it?). As the afternoon wears on, the guests grow restless; it's time to fire up the grill and get those ribs cooking. You open up the gas valve, push the ignition button and vrwoosh! a huge fire ball shoots up from the grill. After shutting it down and inspecting the innards, you determine that the heat shields (technically called flame tamers) have disintegrated into what looks like charred Frosted Flakes. Your grill has suffered an acute case of corrosion. As Brother David rushes to the scene with excited cries of "I can fix it!" you hurriedly make an exit for the hardware store hoping that the parts you need will be in stock. Wouldn't it be nice if your gas grill components lasted longer? New technology developed at the National Energy Technology Laboratory (NETL) may do just that.

The monetary impact of corrosion on the U.S. economy is estimated to be in excess of a trillion dollars annually.
The monetary impact of corrosion on the U.S. economy is estimated to be in excess of a trillion dollars annually.

Simply defined, corrosion is the deterioration of a metal or a metal alloy due to a variety of factors, such as exposure to moisture, high temperature, and caustic gases. This is not to be confused with rust, which is a type of corrosion specific to iron and metals containing iron. While estimates vary concerning the effect of corrosion on the U.S. economy, recent reports put the total cost of corrosion in excess of $1 trillion dollars annually. Corrosion impacts a wide range of industries including transportation, infrastructure, manufacturing, and utilities. In light of this, a growing area of science is focused on advanced materials and metallurgical processes. Much of these efforts focus on the development and testing of novel or improved structural and functional materials better able to withstand corrosive environments.

The cerium oxide coating can be applied through brushing, spraying, or dipping to ensure complete coverage of complex metal parts of all shapes and sizes.
The cerium oxide coating can be applied through brushing, spraying, or dipping to ensure complete coverage of complex metal parts of all shapes and sizes.

Corrosion is a natural process that is nearly impossible to prevent ("Rust Never Sleeps," so it's been said), but measures can be taken to control the rate at which corrosion occurs. For example, protective barrier coatings can be applied to metal surfaces. Prior to the introduction of galvanized steel into the automobile manufacturing process, it was not uncommon to have your new car undercoated for rust protection. Products such as Rust-Oleum paint contain additives that provide a protective coating to help metal surfaces resist corrosion that results from ambient weather.

While such products and processes may be beneficial under many everyday scenarios, they're no match for the harsh conditions encountered in our nation's coal-fired power plants. The operating efficiency of these plants is directly related to combustion system temperature and pressure, and the harsher the environment, the more efficient the plant becomes. Incorporation of ultrasupercritical steam conditions into new or existing power plants can increase efficiency, but traditional materials cannot withstand these aggressive environments and the functional lifespan of the components is reduced. One approach to address this issue is the use of durable corrosion resistant coatings.

A partially treated flame tamer prior to testing at elevated temperatures (the untreated surface serves as the experimental control). Cerium oxide surface treatment significantly improves corrosion resistance and will extend the useable lifespan of system components.
A partially treated flame tamer prior to testing at elevated temperatures (the untreated surface serves as the experimental control). Cerium oxide surface treatment significantly improves corrosion resistance and will extend the useable lifespan of system components.

An award-winning, patented technology developed by NETL metallurgists, Drs. Paul Jablonski and David Alman, provides a simple, low-cost, and robust method for applying cerium oxide slurry to a variety of metal surfaces. The slurry, in combination with an activator compound, can be applied to the surface of a metal component by brushing, spraying, or dipping. This low-cost process ensures a uniform coating on parts of complex shapes that are difficult to coat using traditional methods. Analysis of the coatings after thermal treatment showed that cerium oxide reacts with the metal surface to form a cerium-rich layer, resulting in a protective surface layer that greatly slows the rate of corrosion. In most cases, the cerium surface treatment improved corrosion resistance by a factor of two to three, and with some alloys it resulted in an order of magnitude improvement in performance. This inexpensive process protects stainless steel and other metal surfaces from heat-induced corrosion, increasing the useable lifespan of system components.

Corrosion Solutions team members Jeff Matthews (L), Jake Heckathorn (C), and Brian Oehler (R) were awarded first place in the Bangkok Business Challenge held in Bangkok, Thailand.
Corrosion Solutions team members Jeff Matthews (L), Jake Heckathorn (C), and Brian Oehler (R) were awarded first place in the Bangkok Business Challenge held in Bangkok, Thailand.

If you're wondering how this technology can improve your backyard grilling experience, read on. As part of the University of Oregon's Lundquist Center for Entrepreneurship's Venture Launch Pathway program, a group of MBA students elected to evaluate this technology for technical merit and commercial potential across a variety of business sectors including barbecue grills. To capitalize on this newly identified opportunity, a start-up company was established. Known as Corrosion Solutions LLC, the company is licensing the cerium oxide coating technology and will initially focus on implementing the technology for surface coating for consumer and commercial gas cooking and barbecue grills. Working closely with NETL they selected applicable materials for the barbecue grill market and have initiated sample evaluation with a destructive testing engineering firm. They have also identified potential partners and vendors, validating value and supply chains for their company and industry. This will ensure that they can secure the appropriate raw materials at reasonable prices and in the required amounts. Further, the company's goal is to source all raw materials domestically as well as to have all products manufactured in the United States. NETL continues to work with the management team at Corrosion Solutions in an advisory capacity, helping to accelerate commercialization.

Work at Corrosion Solutions will initially focus on component surface coatings for gas cooking and barbecue grills.
Work at Corrosion Solutions will initially focus on component surface coatings for gas cooking and barbecue grills.

Corrosion Solutions has currently raised $100,000 in owner contributed capital and is looking to raise an additional $1 million in capital through an external investment strategy with private venture capital partners. The company also looks to increase operating funds through application for Small Business Innovation Research grants and local business accelerators. Second generation applications will be applied to high-temperature heat exchangers and turbine components for enhanced energy efficiency. Projected revenues from these three market segments are expected to reach $30 million by 2017. It is anticipated that the successful commercialization of this technology will initially lead to better consumer products with extended usable lifespan. The introduction of this technology into the steel fabrication process will enhance U.S. manufacturing competitiveness, potentially leading to new job creation. Lastly, transfer and deployment of this technology to the commercial market is in direct alignment with NETL's mission to invest taxpayer funding in advanced technologies that can directly benefit the American public.

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