Metal Corrosion. Electroplating (Защита от металлов от коррозии. Гальванотехника) - страница 18

14. Give the definitions of the words and word combinations.

1. Radiation is …

2. Condensation is …

3. Humidity is …

4. Pressure is …

5. Convection is …

15. Give the example(s) of the atmospheric corrosion.

16. Answer the following questions using texts from Unit 4.

1. What is the definition of atmospheric corrosion?

2. What may cause atmospheric corrosion?

3. Name the principal factors of atmospheric corrosion.

4. What do industrial environments contain?

17. Summarize the general ideas developed in all the texts of the Unit 4.

1. Read the international words, guess their meanings and give the Russian equivalents.

Accelerate, electrical, contact, conductive, galvanic, phenomenon, attack, uniform, nature, service, condition, film, erosion, limit, effective, action, anode, cathode, test, region.

2. Read and translate the following verbs.

To depend on, to remove, to insulate, to reverse, to separate, to utilize, to try, to perform, to allow, to expect, to indicate, to generate, to apply, to diminish, to connect, to match.

3. Match the English phrases from column A with the Russian phrases in column B.

4. Read and translate the text. Summarize it in Russian.

Accelerated corrosion which can occur when dissimilar metals are in electrical contact in the presence of an electrolyte (i.e. conductive solution). An example of this corrosion phenomenon is increased rate of corrosion of steel in seawater when in contact with copper alloys. Galvanic attack can be uniform in nature or localized at the junction between the alloys depending on service conditions. Galvanic corrosion can be particularly severe under conditions where protective corrosion films do not form or where they are removed by conditions of erosion corrosion.

Prevention or Remedial Action: selection of alloys which are similar in electrochemical behavior and/or alloy content; area ratio of more actively corroding material (anode) should be large relative to the more inert material(cathode); use coatings to limit cathode area; insulate dissimilar metals; use of effective inhibitor.

(From www.galvanic-corrosion.com).

5. Read the text again. Decide whether the following statements are true or false.

1. Accelerated corrosion phenomenon is decreased rate of corrosion of steel in seawater when in contact with copper alloys.