Induction Hardening 101: The Basics You Need to Know

Induction Hardening 101: The Basics You Need to Know

induction heating

Induction hardening doesn’t fit in anywhere in the industry of heat treatment – first of all, there is no giant furnace, the cycle times are completed in seconds, and the whole process happens right in front of your eyes and not behind the safety of a furnace chamber. 

For many heat treaters, there’s a single induction machine in the corner of the shop with just one operator who knows how to use it. Why is it still done then? In this post, Tricon Wear Solutions, your provider of the most durable wear plates, share the basics of induction hardening:

What Is Induction Hardening?

Induction hardening is a procedure that is used for hardening surfaces of steel or other alloy components. In this process, the parts that need to be heat-treated are positioned inside a water-cooled copper coil that is then heated above the transformation temperature through the application of alternating current to the coil. 

Induction hardening is often used for steel parts and copper alloys which are both treated and tempered, so they may be induction hardened, too. 

Why Is Induction Used?

There are several reasons induction is used for specific applications. Here are some of them: 

It  Can Perform  Selective Hardening

Induction lets you harden specific parts or portions instead of the entire component, which most furnace-based heat treatments offer. What this means is you can decide which particular portions you wish to harden and not worry about all the other components that don’t need hardening. 

It Can Improve Strength

Aside from hardening specific parts, the stress known as residual compressive stress induced into the part will then make it stronger. While other processes can perhaps match the improved wear resistance and the improved hardness, they’re unlikely to meet the strength that the induction-hardened part has.

It’s a Single Piece Flow

As mentioned, induction hardening isn’t a batch process because only one part is hardened at a time. That means the induction machine can be placed in its own manufacturing cell and not interrupt the process flow which cannot be said for other types of heat treatment. It’s perhaps one of the reasons even some metallurgists shy away from this process. In fact, when you ask some, they’d tell you they’ve heard of induction hardening but all they know is that there’s a coil and that’s all they know about it. 

Equipment and Tools

Induction Hardening Machine 

Systems vary, both in size and complexity and it mainly depends on the components that they need to harden. The main components of the machine include a power supply, a transformer or heat station, a workstation, and the HMI. 

The fluid system is made up of quenchants to cool the part that is being hardened and distilled water to cool the components inside the machine. Heat time, part rotation, power supply output, and quenchant parameters need to be controlled and monitored.

Power Supplies

These are the most important part of the induction hardener. Its two most important outputs are frequency and power. Frequency matters because it helps determine the depth of heating. Higher frequencies heat much closer to the surface while lower frequencies heat deeper.

Power is important because of the fact that it determines how large of a portion you can harden and how long it needs to be heated. The more power a machine can deliver the bigger the part it can harden. 

Coils

The copper conductor induction coil hardens the specific area of the portion and the current flowing through it is what creates the magnetic field that heats the part. Coils are part-specific because they have to be precisely constructed so they can heat a specific portion of the part.

Conclusion

The information you found in this article is just an introduction to the fundamentals of induction hardening. Similar to other forms of heat treatment, it could take many years to know everything about induction hardening and gain the skills necessary to perform this task. If you have a need for induction heating or other operations like fabrication and hardfacing welding, it’s better to entrust it with reputable professionals. 

Tricon Wear Solutions handles the production of any component or assembly. We perform induction hardening,  roll and press forming, fabrication, and hard facing, among others. Our metallurgical department can handle any task you might require. Contact us today to know more about our services!

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