3. Welding

Welding is a joining technique that restores metallic continuity between two elements of an assembly. It is used in mechanical engineering to :

• production of complex parts;

• reduce scrap (chips, burrs, etc.) in manufacturing ;

• overcome certain constraints linked to forging and casting (draft, etc.).

It often leads to a better use of metal, as it can be used only where it is needed (resulting in mass savings).

However, it creates significant localized thermal effects, resulting in transformations, deformations and residual stresses that the mechanic has to master. However, the situation becomes very favorable when, as is often the case in mechanical engineering, a complete heat treatment is carried out after welding....