2. Finishing heat treatments

2.1 Presentation

These heat treatments are designed to modify the characteristics of materials to strengthen mechanical parts. They mainly affect hardness, fracture resistance, impact strength or ductility. They also have a beneficial effect on friction properties, corrosion resistance, magnetic properties and dimensional stability.

In a heat treatment, the material undergoes a thermal cycle based on heating at a set rate, holding at one or more temperatures, followed by cooling at a controlled rate. A distinction is made between the following heat treatments.

• Surface treatments induce specific surface properties. A distinction is made between thermochemical treatments, which modify the chemical composition of the...