Protsesslõõmutamine

Protsesslõõmutamine, also known as process annealing, is a heat treatment process applied to metals and alloys during their manufacturing. It is performed at specific stages of fabrication, typically between cold working operations, to reduce the effects of work hardening and restore ductility. Work hardening occurs when a metal is deformed at room temperature, making it stronger but also more brittle.

The primary goal of process annealing is to soften the material enough to allow for further deformation without fracturing. This is achieved by heating the metal to a temperature below its lower critical temperature, but above the recrystallization temperature. At this temperature, new, strain-free grains begin to form within the deformed microstructure, a process called recrystallization. This recrystallization relieves internal stresses and restores the metal's ability to be shaped.

The specific temperatures and holding times for process annealing vary depending on the type of metal, its initial condition, and the extent of cold working it has undergone. Common examples of where process annealing is used include the manufacturing of wires, sheets, and tubes, where multiple drawing or rolling operations are required. It is a crucial step in ensuring that metal products can be formed into their final complex shapes without defects. Unlike full annealing, process annealing does not typically aim for the softest possible state, but rather for a balance between ductility and strength suitable for subsequent manufacturing steps.