Heat Treatment

Question 1

Can a structure stay in the austenite phase

Answer 1

No, when the material is cooled it will be of a different composition

Question 2

define quench

Answer 2

the rapid cooling of a material, transforms austenite to martensite

Question 3

define annealing

Answer 3

heating a material to an elevated temperature to improve ductility
- soak (hold at high temp)
- cool slowly (in a furnace)

Question 4

what are the two types of annealing

Answer 4

full:
transform structure such that coarse pearlite is achieved
process:
cheaper, raised to low temp, cooled quicker, pearlite with ferrite formed (used for work hardened parts: cold form, drawing, extrusion, etc)

Question 5

how do you stress relief

Answer 5

• heat (around 600°C)
• hold
• cool slowing

Question 6

what is tempering

Answer 6

follows quenching to transform martensite to spheroidised cementite, produces rounded particles

Question 7

What is normalising

Answer 7

Similar to full annealing, but produces fine perlite as its cooled at a slower rate

Question 8

What is quenching

Answer 8

Rapidly cooling material to room temperature, austenite to martensite