Definition
A heat treatment applied to cold-worked metal in which the metal is heated to a temperature below its critical range, held briefly, and then allowed to cool. Process annealing softens the metal and restores ductility so that further cold working can be performed without cracking.
Plain English
A way of softening metal that has become hard and brittle from being bent, rolled, or hammered, so it can be worked again without breaking.
Context Anchor
Seen in aircraft maintenance and metal repair discussions, especially when steel sheet or small steel parts have become hard from bending, rolling, or forming.
Derivation
Anneal comes from the Old English onaelan, meaning to set on fire or to bake. In metalworking it has long meant heating metal to soften it. Process annealing is annealing done as a step in the manufacturing process, not as a final treatment.
Why Pilots Care
Restores formability to steel parts so they can be bent or repaired without cracking, preserving structural integrity during maintenance.
Analogy
It is a little like warming stiff material so it can be shaped without breaking. The heat is controlled carefully; it is not meant to burn, melt, or ruin the material.
Grounding Statement
The slow cooling lets internal stresses relax so the metal stays workable instead of becoming brittle again.
Intuition Check
Process annealing does not mean simply heating a part until it is hot. It means controlled heating below a critical change point so the metal becomes easier to form without being fully re-treated or melted.
Example Sentence 1
After several passes through the rolling mill, the sheet metal was given a process annealing to restore its workability.
Example Sentence 2
After cold-forming the new firewall panel, the technician used process annealing to return the steel to a ductile condition.