Chapter 14 - Tempering Flashcards
Does tempering harden metal or soften it?
Soften
Define tempering?
process of reheating a steel to a temperature below its lower transformation temperature and cooling it at any rate.
Why is tempering also referred to as drawing?
Because it drawback the hardness of steel.
The purpose of tempering is to increase
ductility reduce internal stress.
Of the following, select all the properties normally improved by tempering.
a) Strength.
b) Hardness.
c) Ductility.
d) Shock resistance.
e) Toughness.
- Ductility.
- Shock resistance.
- Toughness.
When is tempering not desirable?
Welding
What is the standard range in temperature used for tempering metal?
160-650C
300-1200F
How long is a typical wait after a sample has been quenched before beginning tempering?
No waiting period
What final structure of steel is produced by the general quenching and tempering process?
Tempered martensite
What is the difference between general quenching and tempering and martempering?
Upon quenching, it is held between 500-600F then finished quenching by making the process a little more gentle.
What special quenching method produces 100% bainite?
Austempering
What final structure of steel is produced by isothermal quenching and tempering?
Bainite and tempered martensite
What is the name given to the special tempering process wherein a metal is quenched to a temperature of about 500F to 600F, held there for a few seconds, quenching to martensite, and then tempered?
Martempering
What is the name given to the special tempering process wherein a metal is quenched to a temperature of about 500F to 600F and held at that temperature until bainite is formed?
Austempering
Which of the four quenching and tempering processes is considered to be the most drastic?
General tempering
