Задание для студентов 205 группы на 20.01.2021

Задание 1.

Прочитайте данные ниже слова и словосочетания, подберите для них соответствующие русские эквиваленты:

Combustion, pass, in respect, are affected, obtain, equal, essence, incandescent, conform, subject, distinguish, surrounding media, are attacked, lacquer, uniform, destruction, destroy, action.

в отношении, покрывать лаком, сгорание, получать, сущность, раскаленный, соответствовать, повреждаться, разрушаться, равный, различать, равномерный, разрушать, проходить, окружающая среда, действие, подвергать, исходный.

Задание2.

Переведите на русский язык следующие словосочетания с помощью словаря.

subject to the action of atmospheric air

beginning from the surface

lose their initial appearance

exposed to an external aggressive (active) medium

equal intensiveness

only separate structural components

the laws of chemical kinetics

the oxidation and erosion of the valves of internal combustion engines the oxidation and erosion of the valves of internal combustion engines

incandescent products of combustion

the essence of electrochemical corrosion

Задание 3.

Переведите на русский язык следующий текст с помощью словаря:

CORROSION OF METALS AND ALLOYS

Almost all metals and alloys subject to the action of atmospheric air or other surrounding media (for example, sea water, soil, acid and alkali solutions, organic liquids, etc.) are gradually destroyed, beginning from the surface, and lose their initial appearance. This progressive destruction of a metallic surface exposed to an external aggressive (active) medium is called corrosion.

Experience shows that corrosive destruction depends mainly upon the following three factors: (1) the chemical nature of the metal or composition of the alloy and their structures;

(2) the chemical nature of the surrounding medium and the percentage of aggressive matter in metals (oxygen, moisture, acids, alkalis, etc.),

(3) the temperature of the surrounding medium.

As to its character, metal corrosion may be classified as: (1) uniform corrosion, in which the whole surface of the metal or alloy is corroded with equal intensiveness; (2) localized corrosion, in which only certain areas of the surface are attacked; (3) selective corrosion, where only separate structural components of an alloy are affected and (4) intercrystalline corrosion, which involves destruction of the metal or alloy along its grain boundaries.

According to the mechanism of the corrosion process, it is necessary to distinguish between chemical and electrochemical corrosion.

Chemical corrosion conforms to the laws of chemical kinetics. A typical example of chemical corrosion is the oxidation and erosion of the valves of internal combustion engines by the incandescent products of combustion. A film of corrosion products, usually oxides, is formed on the surface of metal in the course of chemical destruction. In some cases this film may protect the underlying metal

against further corrosion, i. e. make it more passive in respect to the surrounding medium.

Electrochemical corrosion occurs in the presence of liquids which are electrolytes containing free ions. The essence of electrochemical corrosion is that the atoms, on the surface of the metal in contact with the electrolytic solution, pass into the solution as ions and leave an equivalent quantity of electrons in the metal.

The principal corrosion protection methods applied in practice are: (1) alloying metals to obtain chemically inactive alloys of special composition; (2) forming oxide films on the surface of metal parts; (3) applying protective metallic coatings on the parts; (4) protecting the surf ace of metal with a coat of paint or lacquer.

Задание 4.

Ответьте на вопросы к тексту и составьте краткий пересказ текста:

1. What process is called corrosion?

2. What factors, does corrosive destruction depend upon?

3. How may metal corrosion be classified?

4. What is a typical example of chemical corrosion?

5. What is the essence of electrochemical corrosion?

6. What are the principal corrosion protection methods?

Задание 5.

Заполните пропуски в предложениях в соответствии с содержанием текста:

1. The progressive destruction of a metallic surface is called __________________.

2. The metals subject to the action ______________.

3. Chemical corrosion conforms to ____________________.

4. A film of corrosion products is formed on _________________.

5. The film may protect the underlying metal against ______________.

6. Electrochemical corrosion occurs in the presence of liquids __________________.