Heat Treatments

Question 1

What is the purpose of heat treatments in processing techniques?

Answer 1

Altering the properties of metal with heat

Heat treatments can modify characteristics such as hardness, toughness, and ductility.

Question 2

What is hardening in heat treatment?

Answer 2

Heated and quenched in water; increases hardness and brittleness

This process makes the metal harder but also more brittle.

Question 3

What is tempering?

Answer 3

Heated below critical point and slowly cooled; increases toughness and ductility

Tempering is often used after hardening to alleviate brittleness.

Question 4

What is case hardening?

Answer 4

Bar carburizing and quenching; increases surface hardness while maintaining inner core

This process is used to improve wear resistance of the surface.

Question 5

What is annealing?

Answer 5

Heating and slow cooling of work-hardened metal; increases ease of work and reduces brittleness

Annealing helps restore ductility to metals that have become hard and brittle.

Question 6

What is normalizing?

Answer 6

Heated and quickly quenched, then left to cool; increases ductility and toughness in low carbon steel

Normalizing is used to refine the grain structure of steel.