Can I induction harden this part?

This is a question that we hear quite often at Zion Industries. Usually the answer is, Yes! Induction is a very versatile method of heat treat and has many applications, but every once in while we get stumped.

When are asked this question we will first have questions of our own. Is this material that be can be hardened? Is there proper carbon content? The material will only hardened to its maximum hardness based on the carbon content, this is mostly true regardless of the heat treat method used. Is this material suitable for induction hardening? This can be a bit tricky as the material may have plenty of carbon, but the structure is not a suitable structure for induction hardening. Because the induction heat treat happens so quickly some materials will not go into “solution” quickly enough, and the heat treat ends up being spotty or just too soft.

Is the depth of hardness appropriate? Induction is best suited for shallower depths, it is by definition a “case hardening” process. We at Zion have processed parts with of up to ½” of case depth if the hardenability of the material is suitable. As a general rule of thumb most of the higher alloy steels will allow a deeper case depth than regular carbon steel.

Ok let’s assume that the steel chosen is appropriate, what now? We’ll probably have a few more things that we’ll ask questions about or need to consider. We will review part geometry and factors that may cause concerns regarding cracking or distortion. Induction is a very controllable process and usually the resultant distortion can be controlled much better than with other heat treat methods.

What about bores, can I induction harden this bore? Usually the answer is, Yes! But some bores due to small size or geometry may prove to be difficult.
Can Zion Industries induction harden a long shaft? Well that depends, we routinely induction harden parts up to 5 feet of heat treat length, and depending on geometry and weight can handle parts that are even longer.
What about the weight, this part weighs over 100 lbs? That’s usually not a problem, we heat treat parts that weigh several hundred pounds and parts that weigh just a few grams, and everything in between.

Ok, I think I understand but what if I have some more questions? We would be happy to help answer your questions and better explain if the piece you are looking to have heat treated is a suitable candidate for induction hardening. At Zion Industries our staff will assist you with questions you may have and at times we are even asked to get involved with our customer’s customer, to help them better understand the induction process. We would love to hear from you with any question you may have! 

Lou Ghinga
Estimator
Zion Industries, Inc.