Reading

Task 4. Read and translate the text. Find in the box the opposites to the italicized words from the text.

safe, artificially, cheap, often, wet, remoteness, promotion, seldom, few, similar, acceptance, narrow, solution

Corrosion phenomenon

Corrosion is a naturally occurring phenomenon commonly defined as the deterioration of a substance (usually a metal) or its properties because of a reaction with its environment. Corrosion can cause dangerous and expensive damage to water and wastewater systems, pipelines, bridges and public buildings.

The science of corrosion prevention and control is highly complex, exacerbated by the fact that corrosion takes many different forms and is affected by numerous outside factors. Corrosion professionals must understand the effects of environmental conditions, type of product to be processed or handled, required lifetime of the structure or component, proximity to corrosion causing phenomena and other considerations before determining the specific corrosion problem and specifying an effective solution.

There are ten primary forms of corrosion, but it is rare that a corroding structure or a component will suffer from only one. The combinations of metals used in a system and the wide range of environments encountered often cause more than one type of attack. Even a single cell alloy can suffer corrosion from more than one form depending on its exposure to different environments at different points within the system. All forms of corrosion with the exception of some types of high temperature corrosion occur through the action of the electrochemical cell.

Corrosion of metallic materials can be divided into three main groups: 1) wet corrosion, where the corrosive environment is water with dissolved species; the liquid is an electrolyte and the process is typically electrochemical; 2) corrosion in other fluids such as fused salts and molten metals; 3) dry corrosion, where the corrosive environment is a dry gas; dry corrosion is also frequently called chemical corrosion and the best-known example is high temperature corrosion.

No material is resistant to all corrosive situations but materials selection is critical to preventing many types of failures. Factors that influence materials selection are corrosion resistance in the environment, availability of design and test data, mechanical properties, cost, maintainability, compatibility with other system components, life expectancy, reliability and appearance.

Task 5. Answer the following questions to the text.

1. How is corrosion commonly defined?

2. What damages are caused by corrosion?

3. Why is the science of corrosion prevention and control highly complex?

4. Why is it rare that a corroding structure or a component will suffer from only one primary form of corrosion?

5. How do all forms of corrosion occur?

6. What groups can corrosion of metallic materials be divided into?

7. What is the corrosive environment in wet corrosion?

8. What is the corrosive environment in dry corrosion?

9. Why is materials selection critical to preventing many types of failures in corrosive situations?

10. What are the main factors influencing materials selection to prevent corrosion?

Task 6. Decide which of the following statements are true (T) or false (F). If the statement is false, explain why.

1.	Corrosion involves the deterioration of a metal and degrades its useful properties because of a reaction with its environment.
2.	Dangerous and expensive damage can be caused by water and wastewater systems, pipelines, bridges and public buildings.
3.	Corrosion takes many different forms and is influenced by numerous external factors.
4.	The effects of environmental conditions, the required lifetime of the structure and other considerations must be understood by corrosion professionals.
5.	It is often that a corroding structure or a component will suffer from only one form of corrosion.
6.	The combinations of metals and the wide variety of environments often give rise to more than one type of attack.
7.	Even a single cell alloy can experience corrosion from more than one form depending upon its exposure to similar environments.
8.	Corrosion of metallic materials can be classified into three main groups.
9.	Wet corrosion is frequently called chemical corrosion.
10.	Corrosion resistance is one of the factors influencing materials selection.

Task 7. Match the columns to make the phrases and translate them.

1) corrosion	a) conditions	1)
2) molten	b) cell	2)
3) materials	c) properties	3)
4) electrochemical	d) systems	4)
5) complex	e) salts	5)
6) environmental	f) metals	6)
7) dissolved	g) resistance	7)
8) mechanical	h) selection	8)
9) wastewater	i) science	9)
10) fused	j) species	10)

Task 8. Complete the phrases with the words from the text.

1. to be defined as_______ of a substance

2. to be affected by_______ outside factors

3. to specify an effective_______

4. to understand the effects of _______conditions

5. to cause_______than one type of attack

6. to occur through the action of_______cell

7. to influence _______ selection

8. to depend on_______ to different environments

9. to be divided into _______ main groups

10. to be resistant to all_______ situations

Task 9. Match the words from the text with their definitions and compose your own sentence with the following words to illustrate their use.

1.	phenomenon	a.	capable of forming a chemically stable system
2.	reaction	b.	the beginning of destructive action
3.	deterioration	c.	change or transformation in which a substance decomposes or combines with other substances
4.	proximity	d.	capable of being used in a chemical reaction
5.	prevention	e.	the complex of physical and chemical factors, the circumstances, objects, or conditions by which one is surrounded
6.	environment	f.	the act or practice of stopping something bad from happening
7.	resistance	g.	the act or process of becoming worse
8.	attack	h.	the state, quality, sense, or fact of being near or next
9.	availability	i.	an occurrence, circumstance, or fact that is perceptible by the senses
10.	compatibility	j.	the ability to prevent something from having an effect

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