Annealing is often described as “a process used to induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties”. For stainless steels this process typically includes heating and holding material to temperatures in excess of 1900° F, and then cooled (at varying rates) to ensure proper characteristic transformation.
At Jayne industries our procurement department ensures the acquisition of drawn and annealed stainless wire prior to forming. A secondary annealing process if specified is offered by Jayne.
Solution annealing is often known as dark annealing because it can cause a carbon or soot build-up on the material upon completion of the process. This build-up or coating can cause complications during material identification testing. To properly test for material identification one must buff or sand off the dark buildup to a clean shiny state before testing.
Bright annealing takes place in an atmosphere controlled furnace such as a vacuum where atmospheric characteristics are tightly controlled and oxidization is kept to a minimum. The end result of this process is a part that is clean and relatively shiny. As this process is usually carried out in a batch style furnace such as a vacuum furnace, this process can be expensive and redundant to the refractory industry as the purpose is usually to present an esthetically pleasing part for showcase.