While a metal’s chemical composition determines its mechanical composition, manufacturing industries can alter its mechanical properties through heat treatment. Companies use different methods, and one of them is annealing. If you’re looking to get more information about this process, this blog will help you learn some of the essential things to know about annealing.
What Is Annealing?
Annealing is a heat treatment process that changes the physical and chemical properties of a material to increase the ductility and reduce its hardness to make it easy to work curves and perform other processes. Before the material is annealed, it undergoes a cold working or hardening process to make it more formable and prevent brittle failure.
How Does Annealing Work?
Annealing involves three steps:
Recovery: In this process, metal is composed of lattice crystal structures called grains. These structures can cause stress to the metal. A furnace or other heat sources are used to increase temperatures to relieve internal stresses.
Recrystallization: During this stage, the material is further heated to extremely high temperatures to raise the metal’s temperature below its melting point but high enough to recrystallize. This is done to allow the formation of new grains without stress.
Grain growth: At this point, new crystal grains become fully formed as the metal cools without the initial stress. This growth is controlled by allowing the metal to cool at a specific rate. The result is a material with a reduced hardness and increased ductility. The metal is now ready for stamping, forming and shaping.
Why Should You Anneal Metals?
Annealing is a critical process used to reverse the effects of work hardening, which occurs during cold forming, bending or drawing. If the material gets too hard, working with it can be cumbersome as it leads to cracking. Annealing also eliminates the stresses that occur when welds solidify. Residual stresses can cause cracks and other mechanical complications. Another reason for annealing is improving machinability. Any material that is too brittle can cause excessive tool wear. Eliminating hardness helps reduce the wearing of the tools being used.
Which Metals Can Be Annealed?
Some of the most commonly annealed metals in the manufacturing industry include cast iron and steel. Companies also anneal unique types of copper, aluminum and brass. Brass and copper can be cooled using water, while steel needs to be cooled in the open air.
When Are Annealed Metals Mostly Used?
Metal sheets such as galvanized steel sheets and cold rolled steel sheets are annealed for cold rolling purposes, which can create too much hardness that inhibits further processes. Annealing helps maintain formability and ductility, allowing further punching, bending, stretching and cutting. Aluminum is also annealed to allow extreme drawing and forming operations that would otherwise lead to breaking and cracking of the metal. The deeply drawn parts are fully annealed, dead-soft or tempered.
Get in Touch for High-Quality Annealing and Other Metal Heat Treating Services
J.F Heat Treating Inc. offers comprehensive metallurgical services in North Carolina to alter manufacturability and increase the strength of your materials. Whether you need annealing, quenching, aging or tempering, our team can help you achieve them at affordable rates. Call us at (704) 864-0998 for more information.