Engineering Materials - Study Mode

[#131] Specify the sequence correctly
Correct Answer

(C) Stress relief, recrystallization, grain growth

Explanation

Solution: the correct sequence is described are under as: Stress relief, recrystallization, grain growth

[#132] Cementite consist of
Correct Answer

(D) 6.67% carbon and 93.33% iron

Explanation

Solution: Cementite consist of 6.67% carbon and 93.33% iron It has an orthorhombic crystal structure.

[#133] Preheating is essential in welding
Correct Answer

(A) Cast iron

Explanation

Solution: Preheating minimizes the temperature difference between the welding arc and the base material. . Slowing the cooling rate also allows hydrogen to escape the weld puddle as it hardens to help minimize cracking. preheating introduces the necessary heat into the weld area to ensure proper penetration.

[#134] Which of the following material has nearly zero coefficient of expansion?
Correct Answer

(C) Invar

Explanation

Solution: Invar is a solid solution, it is a single-phase alloy, It consisting of around 36% nickel and 64% iron. And uniquely it has nearly zero coefficient of expansion.

[#135] When filing or machining cast iron makes our hands black, then it shows that ________ is present in cast iron.
Correct Answer

(B) Free graphite

Explanation

Solution: When filing or machining cast iron makes our hands black, then it shows that free graphite is present in cast iron.