What Is Annealing And Why Is It Important?

If you've ever looked closely at a vehicle's air conditioning system or engine radiator, you've probably noticed the many tightly woven aluminum tubes. Whether it's forming complex tube designs, robust pipes, or thin conductive wires, metal production is a multi-stage science. Understanding how your product will be used and the specifications it needs to meet is vital to optimizing your annealing equipment and processes so you can deliver a quality product every time.

What is annealing and why is it important?

Forming metal into cylindrical pipes, tubes, and wires requires multiple stages of forming and stretching to achieve the required diameter and thickness. But this material can only be processed so many times before its natural crystal structure changes and it becomes 'work-hardened'. As the name suggests, work-hardening means that the metal is processed several times and hardened to the point of becoming brittle. By attempting to work harden the metal further, you may break it or damage the tooling used to draw the material into shape.

Connecting Rod Induction Annealing Equipment

Annealing process

Annealing is a heat treatment process that counteracts work hardening by changing the properties of the metal, restoring the material to its original crystal structure and elasticity. This critical step allows the metal to continue through additional forming processes, ensuring product integrity and making transportation and storage feasible. Annealing is used in many different metal industries, from API pipe welding, and copper and aluminum tube production to wire production, and more.

Induction annealing

More specifically, induction annealing uses induction heating to precisely control the temperature during the annealing process. It heats uniformly and precisely controls the heating time and temperature to obtain the correct characteristics of the product produced.

What happens if a pipe, tube, or wire is not annealed?

Depending on the product, the consequences of not annealing can range from inconvenient to horrific. Imagine trying to transport wire that will break when bent. This fragile material would have to be cut to straight lengths to fit into a truck car, train car, or container, not to mention cobbling it together to wire a building or car, or for transporting electricity.

And the copper tubes that help cool car engines (and passengers)? If the copper is not annealed, it could shatter and break when the manufacturer first tries to roll it into the compact space under the bonnet.

Alternatively, consider the piping used to transport oil and fuel. The American Petroleum Institute (API) sets strict standards for these pipes, as they must withstand rugged terrain and enormous pressures. Cracks in the welds can lead to catastrophic leaks.

Whatever form the metal must take, annealing removes unwanted hardness so that wire can be wound on spools for transport and storage so that copper pipe becomes ductile to form tight turns, and so that API pipelines have durable, reliable welds.

Features of the connecting rod induction annealing machine:

Adopting a PLC system to separately control the machine tool action and the output power of the machine. Easy operation, Accurate precision control. Material loading is manually, but finished products are collected automatically. High efficiency and stable technology, extremely suitable for bulk production.