Engineering Materials - Study Mode

[#136] When medium carbon steel is heated to coarsening temperature
Correct Answer

(C) The grain size increases very rapidly

Explanation

Solution: When medium carbon steel is heated to coarsening temperature the grain size increases very rapidly

[#137] Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
Correct Answer

(C) Manganese

Explanation

Solution: It is a mild deoxidant acting as a cleanser taking the sulphur and oxygen out of the melt into the slag. It increases the harden ability and tensile strength but decreases ductility. It combines with sulphur to form globular manganese sulphides, essential in free cutting steels for good machinability.

[#138] Recrystallization temperature is one
Correct Answer

(B) At which new spherical crystals first begin to form from the old deformed one when a strained metal is heated

Explanation

Solution: Recrystallization temperature is one, at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated.

[#139] The lower critical point for all steels is
Correct Answer

(C) 723°C

Explanation

Solution: The lower critical point for all steels is at 723°C

[#140] Tensile strength of steel can be safely increased by
Correct Answer

(C) Adding carbon up to 0.83%

Explanation

Solution: Tensile strength of steel can be safely increased by Adding carbon up to 0.83%