Heat treatment Flashcards
What is the main objective of heat treatment processes?
To understand how heat treatment processes affect the structure and properties of materials.
What is metal hardening?
A process that improves mechanical properties and increases the level of hardness of a material.
How does metal hardening affect the initial material?
It transforms the soft initial material to a much harder, stronger structure.
What is typically done to hardened materials after hardening?
They are usually tempered or stress relieved to improve dimensional stability and toughness.
What is case hardening?
A method of hardening steel by combining low carbon content metal with higher carbon content metal.
What is the benefit of case hardening?
It increases product strength and helps avoid weakening of the iron.
When is case hardening usually performed?
After the formation of the component into its final form.
What is precipitation hardening?
A heat treatment technique that occurs at low temperatures using alloying materials.
What are the three stages of precipitation hardening?
- Solution annealing
- Quenching
- Ageing
What is the goal of solution annealing?
To precipitate metastable phases of alloys and transform inhomogeneities into homogeneities.
What is the significance of quenching in precipitation hardening?
It prevents alloys from discharging by rapidly cooling the material.
What are typical quenching agents used in precipitation hardening?
- Water
- Oil
- Gas
What happens during the ageing process in precipitation hardening?
The oversaturated solid solution transforms into two-phase alloys.
What is the purpose of tempering?
To develop the required combination of hardness, strength, and toughness, or relieve brittleness.
What does annealing primarily aim to achieve?
To alter the metal’s mechanical properties, making it softer and more workable.
What is a common application of annealing?
It is often used after cold working processes to allow the metal to be worked further.
True or False: Tempering is effective in relieving stresses induced by quenching.
True
Fill in the blank: The primary purpose of _______ is to alter the metal’s mechanical properties.
annealing
