Heat treatment

Heat treatment is the umbrella term for all processes in which a material is heated, held and cooled in a controlled way to change its properties. These include hardening, quenching and tempering, annealing, normalising and case hardening. Every heat treatment uses the microstructure transformations of the iron-carbon diagram. For welders two directions matter: heat treatment BEFORE welding (e.g. normalising for a good starting condition) and AFTER welding (stress-relief annealing, tempering, hydrogen bake-out).