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Assessment of Corrosion Education 1 Importance of Corrosion Engineering Education This is a report on corrosion engineering education. The field of corrosion is concerned with the change over time of all engineering solids, including metals, ceramics, glasses, polymers, aggregates, composites, and other materials as they are exposed to environments such as chemicals, stress, radiation, and so on. It is impossible to consider the importance of corrosion engineering education without also looking from a broad perspective at the impact corrosion has on the United States. This chapter, as an introduction to this report, will discuss how that impact motivates concern about the education of the workforce that is either battling corrosion or should be.1 That concern is what led to this report being commissioned. UNDERSTANDING THE IMPACT OF CORROSION AND CORROSION ENGINEERING EDUCATION The continued reliability and safety of the U.S. industrial complex and public infrastructure are essential to the nation’s quality of life, industrial productivity, economic competitiveness, and security and defense. Each component of the public infrastructure—highways, airports, water supply, waste treatment, energy supply, power generation, etc.—is part of a complex system requiring significant investment. Within that infrastructure, in both the private and government sectors, corrosion affects nearly all of the materials and structures used. Corrosion, therefore, 1 Note that this report focuses on postsecondary education—that is, at the university, college, and workforce continuing education levels.
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Assessment of Corrosion Education affects us in everyday life—in the manufacture of products, the transportation of people and goods, the provision of energy, the protection of our health and safety, and the defense of the nation. By discussing the impact of corrosion, this section sheds light on the importance of teaching engineers about corrosion. Figure 1-1 shows a single but vital element of the national infrastructure, an offshore semisubmersible drilling rig that is undergoing intense corrosion as a result of its exposure to saltwater and the moisture-laden, chloride-containing atmosphere. Financial and Nonfinancial Costs of Corrosion Although most people think of rust when they think of corrosion, the term refers not only to the oxidization of iron but can also refer to the degradation of all materials (metals, polymers, ceramics, semiconductors, and so on) that make up the public infrastructure and physical systems as diverse as the nation’s highway network, its military equipment, and medical devices implanted in our bodies.2 The costs associated with corrosion, although largely hidden, are borne by every consumer, user, and producer. They are enormous, estimated to be 3.1 percent of the U.S. gross domestic product (GDP).3 Applying this percentage estimate to the 2007 GDP of about $14 trillion gives a cost in 2007 dollars of $429 billion.4 With a population of 303 million, that works out to $1,416 per person per year in the United States. This estimate is supported by similar estimates in other countries (Box 1-1). The effects of corrosion on safety, health, and the environment are not so readily quantifiable, but failures of infrastructure illustrate the potential for severe impacts on daily life and the economic health and security of the nation. The importance of mitigating corrosion is not just about saving money. It is equally—and in some cases more importantly—about readiness. Operating equipment in severe or unexpected environments can exacerbate corrosion and make systems unreliable. Readiness is critical in such systems as military equipment, emergency response systems, or very specialized systems like the launch facilities of the National Aeronautics and Space Administration (NASA). Often problems 2 For the purposes of this report, the committee will use the term corrosion to refer to the deterioration of a material in its operating or usage environment. NACE International, known as the National Association of Corrosion Engineers when it was established in 1943 by 11 corrosion engineers in the pipeline industry, defines corrosion as the deterioration of a material, usually a metal, that results from a reaction with its environment. While corrosion is associated mostly with metals, the committee considers corrosion to include the degradation of all materials—including polymer, composite, and ceramic materials—that results from a reaction with the environment. 3 For more information, see the Federal Highway Administration study Corrosion Costs and Preventive Strategies in the United States (1999), hereinafter called Corrosion Costs. Available at www.corrosioncost.com/pdf/main.pdf. Accessed February 2008. The report is summarized in Appendix A. 4 GDP data from http://www.bea.gov/national/index.htm#gdp. Accessed April 2008.
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Assessment of Corrosion Education FIGURE 1-1 Offshore semisubmersible drilling rig used in the production of oil and gas. Courtesy of Richard Griffin. occur in locations not easily visible to system operators or users. Figure 1-2 exemplifies this by showing corrosion under insulation in the bilge area of a naval ship. Reliability is also of critical importance in health- and safety-related applications such as biomedical implants, electronics, and sensors. Those organizations, both governmental and private, producing, operating, or maintaining physical structures, objects, and the built environment know that they should be designing systems with protection against environmental degradation. The true cost of any system that has a lifetime longer than a modern commoditized product like a cell phone must take into account corrosion protection, maintenance, and system performance monitoring. In addition to the dollar impact of corrosion there are impacts that are difficult to quantify in terms of money. These are the effects of corrosion on the environment and on society. Clearly, leakage of chemicals, oil, or sewage from corroded tanks, drums, and pipes can have long-term effects on the environment, including the water supply, air quality, contamination of food crops, livestock, buildings, and the wildlife population. Slow leaks of underground fuel tanks have been an ongoing problem; the cost of replacement and decontamination can be calculated
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Assessment of Corrosion Education BOX 1-1 Studies on the Cost of Corrosion A number of studies have been done in the past 60 years in an effort to quantify the losses attributable to corrosion (Table 1-1-1). In 1950, Uhlig estimated that the cost to the United States was about 2.1 percent of the GDP. Similarly, the Hoar report in the United Kingdom showed that corrosion cost amounted to about 3.5 percent of the GDP. The ramifications of this study resulted in the creation of the University of Manchester Institute of Science and Technology Corrosion Centre. A 1974 study for Japan, on the other hand, showed the cost of corrosion was 1.2 percent of its gross national product (GNP). In 1975 for the United States, the National Bureau of Standards and the Battelle Research Institute concluded that the cost of corrosion was 4.5 percent of the GNP. The most recent study, by the U.S. Federal Highway Administration (FHWA) and completed in 2002, estimated the cost of corrosion in 1998 to be 3.1 percent of the U.S. GDP—that is, $276 billion. (This study, referred to in this report as Corrosion Costs, is summarized in Appendix A.) Even though there is scatter in these numbers and it is likely that the 2002 GNP is much more heavily weighted to the service economy and less heavily to materials, assets, and maintenance costs than the 1975 GNP, there can be no denying that the impact of corrosion and environmental degradation on the economies of the developed nations is considerable. TABLE 1-1-1 Studies on Cost of Corrosion Year of Publication Author Country Share of Country’s GDP (%) 1950 H.H. Uhlig United States 2.1 1970 T.P. Hoar United Kingdom 3.5 1974 Japan 1.2a 1975 Battelle/NBS United States 4.5a 2000 DTI United Kingdom 2.5-3.5 2002 NACE/FHWA United States 3.1 aShare of GNP. in dollars, but the long-term effects of contamination of large areas of land cannot be represented simply in dollars. Leaking underground storage tanks are a source of pollutants at many Superfund sites—sites whose cleanup is time consuming and expensive and restricts the use of land and water for many years. In addition to the effects on human and wildlife health and survival of leaks resulting from corrosion, there is the societal cost of injury or death from corrosion-related accidents such as bridge collapses or the corrosion-related failure of medical implants and devices. Whether or not such effects are quantifiable, the overall loss to society and the environment must be considered when assessing the impact of corrosion.
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Assessment of Corrosion Education FIGURE 1-2 Corrosion under insulation in the bilge area of a naval ship. While humanity’s footprint on the global environment may need to be minimized, there will always be a built environment that needs to be protected, improved, and maintained for the safety and well-being of all who live in it. Networks and systems for power transmission, water delivery, and information flow are the fabric that holds modern civilization together, and they call for reliability, maintainability, and sustainability. That corrosion is jeopardizing our nation’s economy, defense, health, and environment is now well documented and motivates a closer look at what this country’s engineers, technicians, and other practitioners who design, manufacture, build, and maintain the national infrastructure are learning about corrosion. Why Corrosion Engineering Education Is Important for Designers, Purchasers, and End Users Designers are responsible for creating products that can perform safely, reliably, and efficiently. They must understand and take into account the operating condi-
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Assessment of Corrosion Education FIGURE 1-3 Corrosion on an automobile operating in a warm, moist chloride environment. While anticorrosion technology for cars has improved tremendously in recent years, this picture shows the extreme corrosion that is still possible. Courtesy of Richard Griffin. tions and possible failure modes. Not anticipating and mitigating corrosion can expose products to a high risk of failure. In the auto industry, severe corrosion of the auto body was once a considerable problem but has been largely overcome by using corrosion-resistant materials and corrosion prevention strategies. Figure 1-3 shows what can happen to an automobile in an aggressive environment. Degradation of structures can result in loss of production or usefulness and, in some cases, of life. The consequences can be very costly and include the possibility of product liability suits. To mitigate these risks, a knowledgeable assessment of the causes and possible prevention of corrosion-related failure or degradation should be incorporated into the design early on. In current design practice, this assessment usually takes the form of a failure modes and effects analysis (FMEA). For corrosion to be adequately addressed, designers need to know about the mechanisms of corrosion failure and to know when they need assistance from a corrosion specialist in selecting materials or operating parameters. Purchasers have the responsibility for ensuring that their chosen system functions safely and efficiently, and they bear the financial burden of its maintenance.
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Assessment of Corrosion Education Those responsible for maintaining our public infrastructure need a sufficient store of knowledge about corrosion engineering to recognize that corrosion has been taken into account in the design process and to estimate the costs of operating the product they have purchased, including the development of a realistic and proactive plan for corrosion mitigation. Roads, bridges, planes, pipeline systems, and the electrical grid are examples of systems where a comprehensive understanding of corrosion can lead directly to lower maintenance costs, longer service lifetimes, and less risk of failure. End users may have little direct connection to the designer but must be confident that the designer has taken corrosion into account. They—and the public at large—must implicitly trust that designers and suppliers are providing goods that are useful for the stated purpose and safe as well. While the monetary cost of corrosion can be estimated, the cost of risks to public safety cannot be so easily measured without performing a complex risk assessment. Public safety and the environment are the main reason end users and the public should be concerned about the state of corrosion engineering education and the implementation of that education by the engineering design workforce. From the evidence the committee examined, corrosion will clearly continue to have a major impact on key industries and infrastructure systems being planned. How industries function and how systems are built will be strongly influenced by their response to the environment in which they must operate. As discussed above, designers of devices and structures, those who purchase them or maintain them, and, of course, their end users should at the very least be aware of the impact of corrosion. The committee hopes that these stakeholders will be among the readers of this report and draws their attention to the following discussion about why they should be interested in corrosion engineering education. The sections that follow describe the crucial role of corrosion in the infrastructure systems that are the lifeblood of the U.S. economy. Transportation Fuels Infrastructure The overdependence on oil of the nation’s transportation system and the pace of global climate change will bring about radical transformations in energy supply and use in the years ahead. The next decade may see the gradual electrification of the automobile with its concomitant dependency on fuel cells, batteries, and the electricity grid. A new set of corrosion problems accompanying this transformation is likely to limit the service lives of the batteries and fuel cells. The production of hydrogen in quantities large enough to make an impact on the transportation infrastructure will probably require thermochemical or electrochemical processes using very high temperatures and highly corrosive solutions. The storage tanks for hydrogen will have to resist degradation such as hydrogen embrittlement.
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Assessment of Corrosion Education FIGURE 1-4 An internal pit in an oil field water injection pipe. Courtesy of Richard Griffin. The storage tanks and pipeline systems for internal combustion engines that are designed to run on ethanol-based biofuels will need to be redesigned, and gasoline additives will need to be developed because of unique corrosion issues and the affinity of these biofuels for water. The present pipeline infrastructure for delivering natural gas, crude oil, and refined gasoline products is also operating at its limits. For example, there have recently been significant failures associated with corrosion at Prudhoe Bay, Alaska.5 Figure 1-4 shows an internal corrosion pit that was found in a water injection system in an oil field. In addition, modifications to gasoline formulations that use renewable resources (ethanol) have now made these formulations more sensitive to water uptake and increased the potential for corrosion during storage and transport. 5 For more information, see http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7020563. Accessed March 2008. Also see http://www.petroleumnews.com/pntruncate/573947058.shtml. Accessed March 2008.
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Assessment of Corrosion Education Engineered Devices and Systems Many new engineering structures employ lightweight materials to save money and energy. Composite structures, ceramics, and reactive metals (such as magnesium) result in less mass in the finished product, but they might require better corrosion protection. Lightweight magnesium is considerably more reactive than steel or aluminum. Graphite composites can be made into very thin, stiff, lightweight structures but will require greater environmental resistance to maintain structural integrity. The push for extended component lifetimes and less design effort means that environmental degradation will become a greater concern. Energy Infrastructure The nation and the world will be challenged to rebuild the energy infrastructure in a way that avoids greenhouse gas emission and maximizes efficiency of electricity production. Wind turbines, solar cells, biofuels, nuclear energy, and clean coal are all set for significant development and increased implementation. Corrosion is likely to be a key issue in solar cell lifetime and wind turbine performance and will become more important in large central power plants. Strategies for scrubbing emissions and capturing carbon will likely be limited by corrosion. Similarly, high efficiencies of central power plants are achieved through the use of very high temperature working fluids, which means much more expenditure for corrosion protection than we see today. As the country considers commissioning more nuclear power plants, the storage and (eventual) disposal of nuclear waste are largely an issue of containment vessel corrosion rates and possible failure modes. Virtually all energy sources will see an increasing cost of corrosion and new forms of corrosion. Therefore, developments in corrosion technology are key to improved efficiency in energy production. Health Care Health care is increasingly dependent on biomedical devices that monitor and control bodily functions and deliver drugs. The drive to minimize size, maximize capability, and extend device lifetime places demands on the materials of construction and on their tolerance for degradation before function is affected. The use of new materials over longer and longer times will require knowing more about the interaction between these materials and the human body environment. Their exposure to drugs will call for such devices to have particularly high resistance to chemical interactions. New uses of such devices and implants are limited by the need for them to resist corrosion for extended lifetimes. As more medical devices are implanted to serve an ever-aging population, unexpected uses and failures can
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Assessment of Corrosion Education FIGURE 1-5 Corroded circuit board. Courtesy of Richard Griffin. occur. However, designers will not be able to solve these problems unless they have extensive training in corrosion science. Electronics and Computers As modern electronic circuitry is reduced to ever-smaller dimensions in order to increase memory and computational density, new problems arise from environmental attack on circuits as their surface to volume ratio increases. The insertion of smart devices and the more widespread the deployment of sensors in all types of systems and structures puts electronics into ever-harsher use environments. Although a cell phone is now a commodity product, the owner still expects that the instrument will reliably switch micro-amp currents through its various switches for a very long time. Corrosion on these contacts can destroy instrument quality and reliability. Sensors are ever more important in daily life, from monitoring biological activity in the body to controlling our cars and providing information on wind, precipitation, chemical contamination, and so on. The increase in sensor utility is driven by advances that shrink the devices to the micrometer level or less, resulting in significantly larger surface areas for the same active volume. The result is that surface and interface corrosion processes will become much more important than they are today and will pose an increasing threat to device and system reliability. Figure 1-5 shows corrosion of a circuit board that had been in a data logger used in a moist environment. National Defense Defense readiness is highly sensitive to corrosion, and future defense systems will still present new challenges as new materials are inserted into defense platforms. Ground vehicles designed for cold war battlefields are being used in desert environ-
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Assessment of Corrosion Education FIGURE 1-6 Examples of corrosion on various bridges. Left: corrosion on the historic Devil’s Elbow Bridge on Missouri Route 66. Courtsey of Conor Watkins, Missouri University of Science and Technology. Available at http://www.rollanet.org/~conorw/cwome/article51&52combined.htm. Right: Rebar corrosion, bridge on 401 Highway in Ontario, Canada. Courtesy of Tim Mullin. Available at www.corrosion-club.com/rebarimages.htm. ments, where the degradation modes are different. The use of smart materials on the battlefield will require robust resistance in aggressive environments. The future soldier will probably be clad in multifunctional uniforms that possess communication capability, power sources, and armor, all of which will require considerable innovation in durability. Exceedingly important from the standpoint of national defense is the impact that corrosion damage has on overall defense readiness. At any given time, 20 to 50 percent of the U.S. Air Force tanker fleet is in repair; many U.S. Army trucks and HMMWVs are in repair or are being used at less than full capacities owing to general wear and corrosion.6 Superimpose on this the huge amount of delayed maintenance and repair of weapon systems and infrastructure of the Department of Defense (DOD) due to the Iraq conflict, and one can see clearly that corrosion, wear, and general systems degradation represent a significant cost for DOD, in the tens of billions of dollars annually. Little is being done to train and prepare present and future professionals in handling this problem properly, and DOD struggles to train its workers to deal well with corrosion. Public Infrastructure The national infrastructure and its maintenance is an important issue (see Figure 1-6). The Bureau of Reclamation at the Department of the Interior faces 6 See the following reports from the Government Accountability Office (GAO) at http://www.gao.gov/cgi-bin/getrpt?GAO-06-709 and the Defense Science Board at http://handle.dtic.mil/100.2/ADA428767. Accessed March 2008.
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Assessment of Corrosion Education serious corrosion-related issues in handling water storage and transport in the Western states, and all municipal water treatment and delivery agencies and infrastructure systems face significant water losses up to the point of delivery due to pipes damaged by corrosion. The corrosion of bridges, decks, and the steel-reinforced concrete structures of our highway system endangers public safety and incurs large outlays every year for such maintenance, which could be reduced by paying more attention to corrosion control at the design stage. The sustainability of the modern infrastructure depends on the proper design and maintenance of its major components, and this in turn demands a cadre of engineers and scientists capable of choosing and using materials so as to minimize environmental degradation. Historical Interest Even our historical artifacts are constantly undergoing degradation and must be maintained to preserve them for present and future generations. Structures and objects from the past require special handling and restoration and protection methods. Bronze statuary of historical interest has become a special problem recently as acid rain has begun to attack bronze alloys that were formerly inert to environmental attack (Figure 1-7). The Statue of Liberty was found to have suffered considerable corrosion when it was restored in the early 1980s.7 Each of the 1,350 shaped iron ribs backing the statue’s skin had to be removed and replaced when it was discovered that the iron had experienced galvanic corrosion wherever it contacted the copper skin, losing up to 50 percent of its thickness. In Our Homes Within our homes, as new building materials are introduced, different corrosion hazards present themselves. Composites that do not degrade like natural materials or metals will be used increasingly in building construction. Connecting the copper piping of a home to steel mains is difficult, as is the incorporation of magnesium anodes for protection of water heaters. See Figure 1-8 for an example of a corroded water heater. In Summary In general, we are pushing the limits of operability with all of the materials we use in the modern world. For instance, the United States is committed to putting manned communities on the moon and Mars and must develop transportation 7 R. Baboian, E.L. Ballante, and E.B. Cliver, The Statue of Liberty Restoration, Houston, Tex.: NACE International (1990).
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Assessment of Corrosion Education FIGURE 1-7 Corrosion on Rodin’s “Thinker.” Courtesy of Philadelphia Museum of Art: Bequest of Jules E. Mastbaum, 1929. and support systems to meet the challenges involved, including those posed by some very unsparing radiation environments. Humanity is expanding into harsher environments on Earth, requiring systems, objects, and structures that can support human activity at great ocean depths, deep underground, and in desert and arctic environments. All of these demands will require a workforce conscious of environmental attack on all types of systems and able to anticipate and design for sustainability under extreme conditions. One of the biggest driving factors is the trend to extend the useful lifetimes of items beyond their original design lifetimes. It is rare to stop using a bridge, for example. Commercial and military aircraft in daily use in the United States are operating well beyond their expected lifetime (Figure 1-9). With a bridge, about 10 percent of the construction cost of the structure controls the lifetime cost. The components of lifetime expense are the costs associated with replacement, readiness, safety, and reliability. The choice often boils down to “pay me now or pay me more later” in design, materials choice, and maintenance. The key to bringing that perspective to design and manufacturing is educating the nation’s engineers.
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Assessment of Corrosion Education FIGURE 1-8 Corroded residential hot water heater. Courtesy of Richard Griffin. BACKDROP TO THE STUDY Proactive corrosion prevention and control can lead to savings in the cost of dealing with corrosion in every area of the economy. But all too often such practices are not employed because of a shortfall in investments or a lack of knowledge on the part of designers. While better and more cost-effective corrosion management procedures could significantly extend the service life of existing systems and reduce maintenance costs and replacement requirements, the value of preventive strategies is often not recognized and they are not even applied. The widespread misconception that nothing can be done about corrosion is exacerbated by the fact that no one is “selling” corrosion. There is no identifiable advocate for corrosion control as there is for, say, the steel or aluminum industries. While there are interested parties, such as the corrosion mitigation industry and professional societies like NACE International, corrosion is not a product per se and there is no national advocate for corrosion programs.
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Assessment of Corrosion Education FIGURE 1-9 On April 28, 1988, Aloha Flight 243 took off from Hilo, Hawaii, bound for Honolulu. As it reached its flight altitude, the cockpit crew heard a loud noise and looked back to see that a part of the passenger roof had blown off the aircraft. The skilled crew landed the plane safely with only one death. The aircraft had been designed to sustain major structural failure and survive. The National Transportation Safety Board (http://www.ntsb.gov/publictn/1989/AAR8903.htm) determined that the probable cause of this accident was the failure of the Aloha Airlines maintenance program to detect the significant disbonding and fatigue damage, which ultimately led to failure of the lap joint and the separation of the fuselage’s upper lobe. Also contributing to the accident were the failure of the Federal Aviation Administration (FAA) to require inspection of all the lap joints proposed by Boeing after the discovery of early production difficulties in the 737 cold bond lap joint, which resulted in poor bond durability, corrosion, and premature fatigue cracking. Government Concern About Corrosion and Corrosion Engineering Education In government circles there is a growing recognition of the need for a better understanding of corrosion and its mitigation. The federal government is investing more resources to preserving the nation’s infrastructure, security, and defense systems and to understanding the true cost of their maintenance. Figure 1-10 illustrates damage done to the flight deck of an aircraft carrier, an example of what corrosion can do to DOD assets. DOD expresses its interest in corrosion as follows:8 8 See http://www.corrdefense.org/CorrDefense%20WebPage%20Content/WhyDODMustProtectItsAssets.aspx. Accessed February 2008.
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Assessment of Corrosion Education FIGURE 1-10 Corrosion on the flight deck of a naval aircraft carrier. The Department of Defense acquires, operates, and maintains a vast array of physical assets, ranging from aircraft, ground vehicles, ships, and other materiel to buildings, airfields, ports, and other infrastructure. Furthermore, in order to perform its mission, DOD must train and fight in all environments, including some of the most corrosively aggressive on Earth. Consequently, DOD assets are subject to significant degradation due to corrosion, with specific effects in the following areas: Safety—A number of weapon system mishaps have been attributed to the effects of corrosion. For example, corroded electrical contacts on F-16s caused “uncommanded” fuel valve closures (with subsequent loss of aircraft), and corrosion-related cracking of F/A-18 landing gears resulted in failures during carrier operations. Readiness—Weapon systems are routinely out of commission due to corrosion deficiencies. For example, corrosion has been identified as the reason for more than 50 percent of the maintenance needed on KC-135 aircraft. Financial—The cost of corrosion to the DOD alone is estimated to be between $10 billion and $20 billion annually. For these reasons, DOD has a long history of corrosion prevention and control. The Department has been a leader in many areas of research (ranging from understanding
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Assessment of Corrosion Education the fundamentals of corrosion to applying advanced materials, coatings, inhibitors, and cathodic protection for corrosion control). DOD is taking action in this area now. It is, for instance, making its concerns felt in the area of military equipment and systems acquisition. A new procurement instruction, DODI 5000.2 (Operation of the Defense Acquisition System), addresses the impacts of corrosion for all procurements over $1 million.9 These developments are linked to the new focus on corrosion found in the FY2007 DOD Authorization Act, which created the position of a corrosion executive and established a policy and oversight office at the Pentagon.10 The legislation instructed that office to draw up a strategy on corrosion prevention and mitigation to include the following: Expansion of the emphasis on corrosion prevention and mitigation within the Department of Defense to include coverage of infrastructure. Application uniformly throughout the Department of Defense of requirements and criteria for the testing and certification of new corrosion-prevention technologies for equipment and infrastructure with similar characteristics, similar missions, or similar operating environments. Implementation of programs, including supporting databases, to ensure that a focused and coordinated approach is taken throughout the Department of Defense to collect, review, validate, and distribute information on proven methods and products that are relevant to the prevention of corrosion of military equipment and infrastructure. Establishment of a coordinated research and development program for the prevention and mitigation of corrosion for new and existing military equipment and infrastructure that includes a plan to transition new corrosion prevention technologies into operational systems. Also relevant is the Senate Armed Services Committee report11 directing the Secretary of Defense, working through the DOD corrosion executive and its Corrosion Policy and Oversight Office, to commission a study under the auspices of the National Research Council (NRC) to assess corrosion engineering education in engineering programs and develop recommendations that could enhance corrosion-related skills and knowledge, which, of course, is the mandate for the present study. In response, the NRC organized the Committee on Assessing Corrosion Education, which was charged to assess the level and effectiveness of existing engineering curricula in corrosion science and technology, including corrosion 9 For a copy of the instruction, visit http://www.corrdefense.org/Key%20Documents/DODI%205000-2.pdf. Accessed February 2008. 10 10 U.S. Code 2228. Available at http://www.corrdefense.org/Key%20Documents/10%20U.S.C.%202228.pdf. Accessed February 2008. 11 Available at http://thomas.loc.gov/cgi-bin/cpquery/T?&report=sr254&dbname=109&. Accessed August 2008.
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Assessment of Corrosion Education prevention and control, and to recommend actions that could enhance the corrosion skills and knowledge base of graduating and practicing engineers. Why a Corrosion Engineering Education Study Is Timely Issues in corrosion engineering are similar but not identical to those encountered in the casting or steelmaking processes. As discussed earlier in this chapter, corrosion subtracts value from materials, while casting and steelmaking add value. All materials degrade with time in their environments. A basic understanding of this process is crucial to the education of the nation’s scientists and engineers. That necessity notwithstanding, a distinction must be made between engineers who should be knowledgeable in materials selection generally and in corrosion specifically (that is, materials engineers) and other engineers who should be aware of corrosion issues but need not be particularly knowledgeable or expert (that is, chemical, mechanical, and civil engineers). As discussed in Chapter 2, there is increasing pressure on engineering curricula to shift their focus to topics that are more closely aligned with current research funding opportunities such as nanoscience and biomedical engineering. At the nation’s research universities reputations are tied to the success of their research, and both faculty and students are attracted to universities with successful research programs. In engineering colleges, research is the fuel that drives the educational engine. Sponsored research provides support for graduate students and laboratory infrastructure, and it attracts top faculty to the field and the institution. Undergraduate programs benefit substantially from research by the trickle-down effect, whereby undergraduates become engaged in research or take courses that focus on topics that have high research profiles. Faculty develop courses based on their research, and their teaching tends to follow their research. As such, areas of science and engineering that are well supported in research attract the top faculty and tend to drive the educational curriculum on both the graduate and the undergraduate levels. Conversely, areas that are poor in research have fewer faculty, fewer courses, and fewer students. While the merit of a strong correlation between research and education is debatable, its existence is not. Unfortunately, and as discussed in the chapters that follow, corrosion as a discipline is suffering nationally from a paucity of research, of faculty, of courses that incorporate the subject matter, and of students interested in the field. As such, corrosion engineering education in the undergraduate curriculum in many engineering colleges today is minimal. The decrease in DOD funding for research directed to corrosion is an important factor in its declining appeal to faculty and students alike. The result is that the workforce now entering industry and government service has little or no training in corrosion, even though the jobs they are taking require an understanding of how corrosion impacts component design and performance.
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Assessment of Corrosion Education This is in contrast to the solid mechanics research community, which has participated thoroughly in developing advanced design approaches to minimize brittle fracture and fatigue failure. The success of mechanics modeling in alleviating mechanical degradation at the design stage has led to it being given a prominent place in the curriculum for many engineering disciplines—for example, aerospace, civil, and mechanical engineering. Success in modeling corrosion could bring important advances in combating corrosion through design and might result in greater emphasis on corrosion engineering in engineering curricula. The motivation for this study, which focuses on the education of the workforce, current and future, is that knowledge-based and skills-based education is critical to preventing and mitigating corrosion at all stages in the life cycle of a product. The FHWA and NACE International study Corrosion Costs made recommendations for preventing or mitigating corrosion.12 Education is the key to carrying out these recommendations: Preventive strategies in nontechnical areas: Increase awareness of the significant corrosion costs and the potential savings. Change the misconception that nothing can be done about corrosion. Change policies, regulations, standards, and management practices to increase cost-savings through sound corrosion management. Improve education and training of staff in the recognition and control of corrosion. Preventive strategies in technical areas: Advance design practices for better corrosion management. Advance life prediction and performance assessment methods. Advance corrosion technology through research, development, and implementation. One key challenge is the decline in student interest in corrosion and in the production of engineers who possess a working knowledge of corrosion. Such a decline threatens to take the field below the “visibility horizon” of both engineering colleges and potential employers of engineering graduates. Corrosion as a subject taught in our tertiary education system is at risk because it is practically nonexistent. The well-documented cost of corrosion to the nation only bolsters the argument that an assessment of corrosion engineering education today is timely and will ensure that the nation not only recovers some of the cost of corrosion but also can rely on the readiness and safety of its critical systems. Role of Corrosion Research In line with its charge, the committee has emphasized education, and although it was not specifically charged with examining corrosion research, the committee recog- 12 The study is summarized in Appendix A of this report. For a copy of the report, see http://www.corrosioncost.com/pdf/main.pdf. Accessed April 2008.
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Assessment of Corrosion Education nizes that research is one of the key vehicles by which graduate education is effected. Accordingly, it looks at the impact that research has on the development of individual faculty members. Research is critical to understanding corrosion and developing new mitigation strategies. Mainly, however, the committee insists that educating engineers and making them aware of corrosion is the first line of defense in ensuring that corrosion is considered during the design process and over the use lifetime. Scope of the Study—Metals and Nonmetals Corrosion, as defined by DOD, the sponsor of this report, is the degradation and loss of function of all materials by their exposure to the environment. Historically, corrosion has meant the destructive oxidation of metals, and this is the way corrosion is often taught. However, the use of materials and the design of new materials are now dominated by nonmetals. Polymers and engineered plastics and composites have been one of the success stories of science over the last 100 years. Between 1980 and 2006, employment in the U.S. plastics industry grew by 1.1 percent per year, and the real value of plastics shipped grew 140 percent, from $114.5 billion to $275 billion.13 Ceramics, concrete, asphalt, and natural stone remain key components of the public infrastructure, but new hybrid organic/inorganic materials, materials based on nanoscale properties, and biomimetic materials are all increasingly in use. Materials development is becoming an atom-by-atom, molecule-by-molecule, or layer-by-layer construction process. This approach to creating new materials with superior properties is sometimes based on scientific principles, sometimes on combinatorial materials design procedures, and sometimes on imitating nature’s own self-organizing processes. Admittedly, some of the combinations of strength, flexibility, and low cost possible with certain metals have not yet been duplicated in new material regimes, nor have the low cost and desirable properties of concrete based on Portland cement been duplicated or significantly improved on. However, the past tells us that new materials free of the weaknesses of current materials will be developed, and many of them will be nonmetallic. While this report is mainly concerned with corrosion engineering education as it pertains to metals, the committee recognizes that nonmetallic materials such as plastics and composites are increasingly being used in applications that up to a few decades ago were the exclusive domain of metals. Indeed the total production of resins—organic polymers, plastics—is now comparable to that of metals, and of this total, a significant fraction is being used in structural applications.14 Contrary to some perceptions, however, plastic materials may be susceptible to interactions that degrade their properties (see Box 1-2). 13 See http://www.plasticsindustry.org/industry/facts/usa.pdf. Accessed April 2008. 14 Alan S. Wineman and Kumbakonam Ramamani Rajagopal, Mechanical Response of Polymers: An Introduction, Cambridge, England: Cambridge University Press (2000).
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Assessment of Corrosion Education BOX 1-2 Degradation of Polymers and the Education of Engineers There are many reasons for the growing use of polymers and composites, only one of which is their perceived enhanced resistance to the degradation of their properties by the environment. The inherent degradability of an organic resin must be modified by compounding it with necessary additives. Absent this important step, the performance and safety of the material will be severely compromised. This susceptibility to degradation varies widely according to the chemistry of the polymer and the environment in which it is used. For example, the fundamental carbon–carbon bond is sensitive to solar ultraviolet radiation, especially in the presence of oxygen. Because of this susceptibility, polymers are seldom employed in the neat form, especially for load-bearing applications. The intrinsic properties of a polymer, including its degradability, can almost always be modified by including one or more additives, which can be selected from a wide range to suit the particular circumstance. Such modification can retard the damage caused, for example, by oxidation. The action of solvents is another reason for property degradation. Solvents may cause undesirable plasticization (lowering the glass transition temperature) and a loss of mechanical strength. Even small amounts of adventitious water, for example, have been known to cause problems in epoxy resins. In addition, certain solvent-polymer combinations may be peculiarly prone to stress crazing and stress cracking. Although polymers in general are relatively immune to biological attack, they are not universally so. Thus aliphatic polyesters are known to be susceptible to certain forms of microbial attack, with negative consequences. To combat these and similar phenomena, a thorough knowledge of polymer properties needs to be acquired by engineers working in the organic materials field. In structural applications where enhanced mechanical or other properties are required, composite materials have become increasingly important. In the present context, a composite can be understood to refer to a multicomponent system in which a high-modulus fiber (say, carbon or glass) is dispersed in a stress-transmitting plastic matrix, frequently one of the thermosetting class of polymers, such as epoxies. The integrity of the composite depends on the integrity of both the matrix and the fibrous component. Technological advances in such composite materials have led to their increasing use in multiple transportation applications, in industrial and domestic infrastructure, and even in small to medium-size bridges. While much of the committee’s data gathering has been in the field of the corrosion of metals, the committee recognizes that environmentally modulated degradation is a pervasive phenomenon that affects all classes of materials. The growing penetration of organics—principally plastics and composites—into the materials arena means that they are also of concern. Property deterioration in organic materials, commonly referred to as degradation rather than corrosion, is, as with metals, a phenomenon that can be alleviated with currently available science and technology, provided that this knowledge is appropriately applied. The fact that cases of polymer and composite failure caused by some form of environmental interaction continue to occur in significant number suggests that education in this area is entirely inadequate. Many but not all engineering curricula pay relatively scant attention to the properties of organic materials, and the phenomena associated with their degradation are often taught only at a superficial level. Even in undergraduate and graduate programs that are dedicated to organic polymeric materials, education in degradation and its mitigation is decreasing, a situation that parallels what is taking place in the metals field.
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Assessment of Corrosion Education The possibility of plastic and composite failure should be a constant concern for design engineers, many of whom have not been taught about this possibility and are therefore far less familiar with this consideration than is desirable. The annual costs of polymer and composite failure due to environmental factors have not been quantified in the same way as the costs of corrosion in metals, but they are certainly significant. As with metallic corrosion, appropriate education of materials engineers and other kinds of engineers in the degradation of plastics and composites must become a tool for dealing with such degradation. OUTLINE OF THE REPORT This report assesses the state of corrosion engineering education in the United States and makes a series of recommendations for improving the situation. Chapter 2 summarizes the committee’s assessments at the undergraduate and graduate levels and looks at what training and on-the-job education are being offered by industry and government. Chapter 3 looks at the impact of the current status of corrosion engineering education on government and industry. It examines whether meeting government and industry needs demands new approaches in corrosion engineering education. For instance, DOD takes an aggressive stance against corrosion, which directly affects its readiness, but it is unclear whether the nation is producing engineering practitioners who can implement the corrosion strategies of DOD and other national entities. The challenges industry faces with regard to corrosion and the scarcity of professional staff knowledgeable about corrosion make for a difficult situation, and the methods used to cope will be described. Industry challenges include the long-term maintenance and safety of structures, pipelines, and highways. The committee draws conclusions and makes recommendations on the direction the United States should follow as it seeks to reinvent its system for educating the engineering workforce in corrosion engineering education.