The benefits of annealing vary by its process. For example, while they both increase the strength of metal, normalization and full annealing deliver different effects that serve different purposes. For businesses that need metal services and wish to learn more about the benefits of annealing, below are its primary benefits and the processes that yield them. For a complete list of processes, contact a metal strengthening service.
Increased Softness
Heat treatment “softens” metal by removing its hardness, which is its ability to resist deformation by indentation. In many instances, hardness is a benefit, though in others, it can make metal difficult to work. Once metals have been worked, they can be tempered to restore their hardness-a scenario that decreases the time and cost of production.
Softening increases a metal’s “cold working properties,” which is its ability to be molded without heat application. Process annealing can soften steel by causing its iron carbide to form into globules-a change that gives steel a marbleized appearance when it is viewed microscopically.
Relief of Stress
When metal is used arduously or exposed to corrosive conditions, it develops internal stress that can reduce its strength. Over time, this stress can cause metal to crack or break, resulting in financial loss and, in some cases, loss of life. Examples of pieces that develop stress at a consistent rate include engine components, contact parts on industrial machinery, large springs that absorb heavy shock and tow bars on tractors.
Normalization, in which a ferrous alloy is heated to a temperature that is above its transformation temperature range, is used to relieve stress in steel.
Improved Brightness
A metal whose brightness is integral to its appeal requires a process that minimizes oxidization. In many cases, the process of choice is bright annealing (also known as stainless steel annealing), which places metal in a vacuum environment or an atmosphere-controlled furnace. The atmosphere can be controlled by placing a bell over the metal in what is known as a bell annealer-a cylindrical machine that can stand several stories tall. Different metals require different atmospheres to produce the desired effect.
Improved Ductility
Improving metal’s ductility can improve its ultimate tensile strength, which is its ability to deform under stress without necking (significantly contracting at its cross section). Ductile metal is required for numerous endeavors, including: commercial plumbing installation, vehicle assembly, and supporting large assemblies with suspensions. Process annealing and full annealing increase the ductility of metal alloys, with the latter creating the highest ductility.
Conclusion
Annealingis an excellent way to extend the lifetime of parts and restore used parts to a “like new” condition. If you need metal that contains minimal stress, excellent ductility, a homogenous crystal structure and has high workability under cold conditions, annealing services can help.
The processes above are only a few of the processes that are available through a metal strengthening service, which may also offer brazing, prototyping, assembly and retrofitting services. To learn more about how these services and others could benefit your business, contact a metal strengthening service.