Sec - 4 (Corrosion Mechanisms)

Question 1

Corrosion would not be expected in ambient temperature crude oil or product service with no ,,,

Answer 1

water present

Question 2

,,,,,,,,,may occur in environmental and product cleanup tanks as well as in chemical storage facilities

Answer 2

Chemical corrosion

Question 3

,,,,,,,,,,,,,may occur when a surface deposit, mill scale, or crevice creates a localized area of lower oxygen concentration.

Answer 3

Concentration cell corrosion

Question 4

Hot-rolled carbon steel, typically used for the construction of petroleum storage tanks, is covered with a thin layer of oxide called mill scale, which is,,,,,,,,, to the base steel

Answer 4

cathodic

Question 5

In some cases, welding can produce large differences in the microstructure of a steel bottom plate resulting in a builtin,,,,,,,,,

Answer 5

galvanic couple