Question

Which of the following characteristics of the impoverished area, results in a rapid corrosion attack?

(a) Less corrosion resistance

(b) The high content of chromium

(c) The large unfavorable area ratio

(d) Less corrosion resistance and large unfavorable area ratio

This question was posed to me during an online exam.

This intriguing question originated from Eight Forms in portion Eight Forms of Corrosion of Corrosion Engineering

Answer 1

Right answer is (d) Less corrosion resistance and large unfavorable area ratio

The best explanation: Rapid corrosion attack in impoverished or chromium depleted zone is due to

i. Less corrosion resistance (As chromium% is decreased)

ii. Two dissimilar metal compositions are in contact (Galvanic effect)

iii. Large unfavorable area ratio is present (Area effect)