Intergranular Corrosion MCQs : Here you will find MCQ Questions related to "Intergranular Corrosion" in Corrosion Engineering. These Intergranular Corrosion MCQ Questions Will help you to improve your Corrosion Engineering knowledge and will prepare you for various Examinations like Competitive Exams, Placements, Interviews and other Entrance Exmaniations
Question 1
Intergranular corrosion (IGC), also known as ?
A. Uniform Corrosion
B. Crevice Corrosion
C. Filiform Corrosion
D. Intergranular attack
View Answer
Ans : D
Explanation: Intergranular corrosion (IGC), also known as intergranular attack (IGA)
Question 2
How much percentage of chromium is minimally required to ensure passivation?
A. 8
B. 10
C. 12
D. 18
View Answer
Ans : C
Explanation: Around 12% chromium is minimally required to ensure passivation, a mechanism by which an ultra thin invisible film, known as passive film, forms on the surface of stainless steels.
Question 3
Intergranular corrosion is a form of corrosion where the boundaries of crystallites of the material are less susceptible to corrosion than their insides.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : B
Explanation: Intergranular corrosion is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides.
Question 4
Which of the following alloys is/are prone to intergranular corrosion?
A. Iron in aluminum
B. Zinc in brass
C. 18-8 Stainless steel
D. Iron in aluminum, zinc in brass and 18-8 stainless steel
View Answer
Ans : D
Explanation: All the given alloys are prone to intergranular corrosion. Iron in aluminum and zinc in brass are susceptible to this corrosion, due to the segregation of iron and zinc respectively at the grain boundaries. Whereas 18-8 Stainless steel is susceptible due to the depletion of chromium at the grain boundaries.
Question 5
which metal is highly Intergranular corrosion?
A. stainless steel
B. zinc
C. silver
D. hydrogen
View Answer
Ans : A
Explanation: Intergranular corrosion (IGC) is a selective attack in the vicinity of the grain boundaries of a stainless steel. It is as a result of chromium depletion, mainly due to the precipitation of chromium carbides in the grain boundaries.
Question 6
What is the minimum percent of chromium is needed to make stainless steel?
A. 0.05
B. 0.07
C. 0.11
D. 0.09
View Answer
Ans : C
Explanation: Stainless steel is a family of iron-based alloys that contain a minimum of 11% chromium. Chromium imparts corrosive resistance to steel.
Question 7
Which of the following is/are the stabilizing elements to minimize intergranular corrosion of stainless steel?
A. Niobium
B. Columbium
C. Both A and B
D. None of the above
View Answer
Ans : C
Explanation: Stabilizing elements are the elements that form strong carbides than chromium. These elements have a much greater affinity to carbon than does chromium, this minimizes the chromium depleted zone.
Question 8
What is the abbreviation of KLA regarding intergranular corrosion?
A. Knife-Line Attack
B. Knight-Line Attack
C. Knife-Life Action
D. Knight-Life Action
View Answer
Ans : A
Explanation: KLA is abbreviated as Knife-Line Attack. Knife-Line Attack is similar to weld decay in that they both results from intergranular corrosion and both are associated with welding.
Question 9
Which of the following is used to visualize the heat flow and temperatures during welding?
A. Intergranular corrosion
B. Tablecloth analogy
C. Weld decay
D. Weld decay and intergranular corrosion
View Answer
Ans : B
Explanation: Tablecloth analogy of heat flow and temperatures is used during welding. To visualize a mountain like a block with the rise and fall of each stripe represents the rise and fall of temperature in a welded plate.
Question 10
Aluminium-based alloys may be sensitive to intergranular corrosion if there are layers of materials acting as anodes between the aluminium-rich crystals.
A. Yes
B. No
C. Can be yes or no
D. Can not say
View Answer
Ans : A
Explanation: Yes, Aluminium-based alloys may be sensitive to intergranular corrosion if there are layers of materials acting as anodes between the aluminium-rich crystals.