Chromate Conversion Coating replacement Term Paper

Chromate Conversion Coating replacement - Term Paper Example This paper focuses upon corrosion as an essential process. It is one of the many ways in which nature recycles its contents. Kamis indicates that it is the destruction or deterioration of materials as a result of reaction with the environment and involves the electrochemical conversion of metals to its original form. Though the process of corrosion cannot be prevented, the rate at which it takes place can be reduced. Kamis in the article entitled â€Å"Cost of Corrosion† indicates that corrosion affects all materials, whether they are metal or non-metal. Chromate coating is a process that is used to reduce the rate of corrosion. Zhao et al indicates that it is a widely used method especially for A1 alloys in aerospace applications as it is considered to be very effective. However, Zhao et al points out that a number of factors including environmental regulations; the requirements for increased service life of airplanes; and the high cost of preventative maintenance has forced the US Air Force to search for other environmentally friendly methods of reducing the rate of corrosion that are also an improvement over the use of chromate. Zhao et al also indicates that an understanding of how CCCs protect metal surfaces against corrosion is fundamental to any research. As Kamis points out a proper understanding of corrosion along with the appropriate engineering application would lead to a major reduction in its damaging effects as well as the costs associated with it. 2.0 Factors influencing chromate replacement There are a number of factors that have contributed to the need for replacing chromate as a coating. They range from environmental concerns which have led to regulations governing the quantities of chromium that is included in certain processes. Additionally, the need to increase the service life of assets means that the replacement required should be able to exceed the level of protection that chromate provides. Furthermore, it needs to be a cost effe ctive technique that will facilitate cost savings in situations where the cost of corrosion preventative maintenance is considered too high. 2.1 Environmental Regulations The National Center for Manufacturing Sciences (NCMS) in their report – â€Å"Alternatives to Chromium for Metal Finishing† points out that the need to find alternatives to replace chromium has been mainly influenced by the effects on the health of humans as a result of exposure to hexavalent chromium which is considered to be a cancer causing agent in humans (1.1). In fact, Pellerin and Booker in their article â€Å"Reflections on Hexavalent Chromium: Health Hazards of an Industrial Heavyweight† indicates that from as early as the 1920’s people who worked in the chrome ore industry in Germany were found to be developing cancer at a rate that exceeded that of the general population (A402). Additionally, people who worked in areas where industrial processes were being carried out suffered from higher rates of both lung and nasal cancers (A402). Therefore, NCMS sees it as no surprise that there are concerns relating to high exposures of the substance in the workplace and the environment generally. NCMS points out that various concerns have led to a number of consequences including: i. increased liability associated with claims for both exposure at the workplace and environmental exposure; ii. increases in the cost of tracking inventories, monitoring and controlling emissions, reporting the use of compounds that consist of chromium, as well as the disposal of waste which contains chromium; and iii. strict rules and regulations relating to the limits for discharging dissolved chromium in waste water (1.1). Kermani and Harr (8) indicate that if corrosion is left unchecked other health and safety issues arise. If plant and equipment are not maintained then the integrity of plant and equipment as well as their serviceability. This will result in leaks and discharge of fla mmable