Write the comparative and superlative forms of the following adjectives and adverbs. Make your own sentences with them.

High, hard, good, long, many, significant, widely, little, early.

8. Complete the following sentences from the text:

1. Thermit welding produces ….

2. Thermit weld is actually as much ….

3. Aluminium plays ….

4. Welding procedures include ….

9. Make your own dialogues using the following words and word-combinations:

To serve as a deoxidizer, weld charge, to ensure weld quality and consistency, alloying elements, thermit welding, localized rail head depressions and deformations, fatigue and deformation resistance.

Retell the text.

SELF-ASSESSMENT

MODULE 4

1. Answer the following questions:

1. What kinds of corrosion do you know?

2. What is the meaning of the word “corrosion”?

3. How many types of corrosion do you know?

4. What is the most dangerous type of corrosion destruction?

5. Why is the joining of soft tissues based on heating called welding?

6. Why is not the laser welding suitable for surgery?

7. What allows fastening surgery performance and reducing blood loss?

8. Will the fields of rational application of welding expand in the future?

9. What is thermit welding?

10. What can aluminium be used for in thermit welding?

2. Give the English equivalents of the following words and word-combinations:

Газове середовище, гетерофазний сплав, оксидна плівка, кількісний коефіціент, недолік, гальмувати, високочастотний струм, специфічні вимоги, самонастройка, клейові засоби, плотність, тигель, розкислювач, взаємовамінення.

3. Are the following statements true or false?

1. Corrosion is a spontaneous destruction of plastic.

2. The structural corrosion is the most dangerous type of the corrosion destruction.

3. The structural corrosion is observed in welded joints of aluminium alloys.

4. Oxide film develops at the boundaries of grains and propagates into the bulk of metal.

5. Operation with application of electric welding tools on man (joining a stomach wound) for the first time in the clinical practice was made in the Central Clinical Hospital in June, 2000.

6. Although widely used in the railroad industry, welding is probably one of the least understood pro the balance of manufacture.

7. The portability, cost-effectiveness and convenience of thermit welding results in its continued extensive use.

8. Thermit welding is actually as much a casting as it is a weld, and consistency may be difficult to achieve.

9. Aluminium doesn’t play a key role in thermit welding.

10. The higher hardness also improves fatigue and deformation resistance and more closely matches the hardness of new head-hardened rails.

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