Heat treatment
Heat treatment changes the steel microstructure through controlled heating, holding and cooling. In practice it is used to set hardness, strength, toughness, dimensional stability and the level of residual stress.
Open interactive module →Topic overview
Heat treatment changes the steel microstructure through controlled heating, holding and cooling. In practice it is used to set hardness, strength, toughness, dimensional stability and the level of residual stress.
Welding creates a heat-affected zone in which some heat-treatment phenomena occur locally. Preheat, interpass temperature, cooling rate and any post-weld heat treatment are therefore important.
A simplified teaching map: exact temperatures always depend on chemical composition, thickness, the applicable standard and the required structure. The essential logic is whether treatment occurs below A₁, around A₁ or above A₃/Acm.
Reduces hardness and improves machinability. The aim is to refine or spheroidise carbides, particularly in carbon and tool steels.
What the module covers
- Heat treatment of steels
- What heat treatment controls
- Relationship to welding
- Where the processes lie in the Fe–Fe₃C diagram
- Soft annealing
- Normalising
- Stress-relief annealing
- Quenching
Continue with the practical module.
Open this topic directly in the interactive WeldScope portal.