ESSAY TOPIC: Every day, thousands of dollars in damage is done to metal structures in our cities by corrosion. What is “corrosion” and in what ways can it be prevented?
Metal in the construction and engineering is a kind of very important material. In our daily life, many things made by metal, for example, use the steamship for transport, use metal build our high-rise buildings… With the increase of human activities in daily life, metal corrosion also occurred in each city, the metal corrosion makes people face every day the thousands of dollars in damage. According to Research Opportunities in Corrosion Science and Engineering [ROICSAE] (2011, p12) “$2 trillion and $4 trillion are lost to corrosion each decade.” From this example, we can see that find the way to prevent the corrosion is very important. If we can find the scientific ways to solve this problem, it can do a great benefit to our society. The purpose of this essay is to explain what is corrosion and will elaborate on how to prevented the loss caused by corrosion. It will discuss what is corrosion, and the chemical reason that caused the corrosion of metal structures. It will particularly focus on the environmental factor as the kind of reason. There will give some examples about the loss caused by corrosion and will give some ways to reduce the economic loss caused by corrosion.
The term corrosion is sometimes also applied to the degradation of plastics, concrete and wood, but generally refers to metals. As the Corrosionpedia(2016) defined that result of steel corrosion is the irreversible deterioration. The reason destruction of the steel material and its vital properties changed due to the electrochemical or chemical reaction of its surface to environmental factors such as acids, moisture and oxygen. The nature of steel corrosion is metal oxidation reaction. “Corrosion is the deterioration a material undergoes as a result of its interaction with its surroundings” (Botana ,2016) Now, corrosion become a hot issue in our daily life. Human activities caused the ratio of carbon dioxide increase, from this, there are more chances to have acid rain. Thus the corrosion rate of steel metal become faster.
There have many factors can have caused the corrosion. The types of corrosion that can occur on steel and metal building structures be divided into basic corrosion, bimetallic corrosion and environmental corrosion. Most corrosion processes involved at least two electrochemical reactions (one anodic and one cathodic). A corroding surface can be thought of as a short-circuited battery; the dissolution reaction at the anode supplies electrons for the reduction reaction at the cathode. (Barbara and Robert, 2006, p24) Corrosion of metal is a very complex process. First, the iron loss of two electrons become ferrous ions [Fe (II)]. Secondly, the ferrous ions again get oxidized into ferric ions [Fe(III)] in the presence of water and oxygen. Thirdly, these...