What is the purpose of heat treating plain carbon steel?
A
To change its color B
To improve mechanical properties C
To reduce its cost D
To increase its weight
Analysis & Theory
Heat treatment is used to enhance hardness, toughness, ductility, etc.
Which process involves slow cooling to soften steel?
A
Hardening B
Tempering C
Normalizing D
Annealing
Analysis & Theory
Annealing softens the steel by slow heating and cooling.
In which process is steel quenched to increase hardness?
A
Tempering B
Hardening C
Annealing D
Normalizing
Analysis & Theory
Hardening involves heating and rapid quenching to increase hardness.
What is the purpose of tempering after hardening?
A
To increase brittleness B
To harden further C
To relieve stress and reduce brittleness D
To increase weight
Analysis & Theory
Tempering improves toughness by reducing brittleness of hardened steel.
What is the cooling medium used in normalizing?
A
Water B
Oil C
Air D
Sand
Analysis & Theory
Normalizing involves air cooling to refine grain size.
Which heat treatment is best for surface hardening?
A
Tempering B
Annealing C
Case hardening D
Normalizing
Analysis & Theory
Case hardening hardens the surface while keeping the core tough.
What is the critical temperature range for plain carbon steels?
A
200–300°C B
400–500°C C
723–910°C D
1000–1200°C
Analysis & Theory
Steel undergoes phase change near 723°C (A1) to 910°C (A3 or Acm).
Tempering is performed after which heat treatment process?
A
Annealing B
Hardening C
Normalizing D
Case hardening
Analysis & Theory
Tempering is done after hardening to reduce brittleness.
Which heat treatment gives fine grain structure and better toughness?
A
Normalizing B
Case hardening C
Tempering D
Hardening
Analysis & Theory
Normalizing helps refine grains and improve strength and toughness.
Which of the following is NOT a heat treatment process?
A
Annealing B
Forging C
Tempering D
Normalizing
Analysis & Theory
Forging is a shaping process, not a heat treatment.