Question

Match the following:

• A. A-I, B-II, C-IV
• B. A-III, B-I, C-II
• C. A-IV, B-III, C-I
• D. A-III, B-IV, C-II

Hint:

Microstructural defects accelerate corrosion by creating electrochemical potential differences.

Answer 1

The Correct Option is D

Concept: Corrosion is influenced by microstructural energy differences: - Grain boundaries → high energy regions - Dislocations → distorted lattice regions - Pearlite → galvanic microcells between phases

Step 1: Match grain boundaries.
Grain boundaries are high energy regions: \[ A \rightarrow III \]

Step 2: Match dislocations.
Dislocations are line defects: \[ B \rightarrow IV \]

Step 3: Match pearlite.
Pearlite has ferrite + cementite phases → galvanic action: \[ C \rightarrow II \] Final Answer: \[ A-III,\; B-IV,\; C-II \]