Induction Heat Treating Success for Metal Parts

For over 40 years Zion has specialized in induction heat treating – a unique process that improves the physical characteristics of very targeted areas on a metal part. It varies from other forms of heat treatment because the part isn’t heated in its entirety, instead induction coils heat localized area using an electric magnetic current while other portions outside of the magnetic field stay unaffected.

In addition to enhancing a property of a part, like increasing or reducing hardness, induction heating allows tighter control over the heating pattern, fast cycle time and higher quality parts.
Before powering up our equipment, every project at Zion starts with a part plan that evaluates these 6 considerations.

Part Planning

Induction heating has many strengths, but like any other heating process, it has its challenges. With proper part and process planning, deficiencies like potential part vulnerabilities can be limited or removed entirely.
Three part characteristics that impact induction heat treating success are determined during the design phase.

1) Part Geometry

We work closely with our customers during the design and engineering stages of many parts. Certain design attributes of a part don’t respond well to heat treating. Crack initiation zones like sharp edges, holes, grooves, slots, shoulders, and corners can weaken and cracks if unevenly heated and cooled.

Designing a part that limits these problem areas can help assure cracking isn’t an issue during the heat treat process.

2) Material

What material will be used for the designed part?
Some steel grades like low carbon steels might not achieve the desired hardness but are less likely to crack. Some higher carbon and alloy steels can achieve very high hardness but increase the likelihood of cracks during heat teat and manufacturing. Zion’s team can help you consider a metal that delivers the required hardness but also provides excellent strength and ductility.

Other factors such as strength and fatigue properties of the material should be considered during the engineering and design stage.

3) Treatment Depth

Depending on the part’s intended application, treatment depth is an important consideration for successful induction heat treating.
Heating a part deeper than necessary can actually “weaken” the part and reduce ductility that affect performance.

Process Planning

Aside from the actual part, the induction heating process requires some planning. Here are three of the process considerations the Zion team reviews induction heating begins.

4) Induction tooling

Induction heating coils are copper conductors formed from tubing or machined from solid copper.

Depending on the part being heated, coils need to be constructed and shaped to meet the needs and geometry of each workpiece. At Zion, we design and develop most of our tooling in house, maximizing our responsiveness and project turnaround time.

In addition to the induction coils Zion also manufactures work-holding fixtures and quench assemblies designed and developed for each application.

5) Induction equipment selection

The Zion engineers select the proper frequency and power levels of the equipment required for each application. With multiple induction power supplies and locations in 3 states we select the best equipment for each application.

6) The induction process and beyond

The induction heat treating process extends beyond the actual heating of the material. The rate of heating the rate of cooling, tempering and material handling must all be considered. With a design process consisting of testing the limits and establishing proper heating cycle, quench parameters including quench temperature and concertation and tempering parameters a robust process is ensured. Zion adheres to the AIAG APQP and PPAP protocols to guarantee a stable and repeatable process for the life of the program.

Many other factors are considered when designing and planning for a large-scale induction heat treating project, such as inspection, packaging, rust proofing, and logistics but these six considerations are fundamental.
Expert planning, by proven industry leaders like Zion Industries, can help deliver your project on time, with lower costs and better-quality parts.

Contact us at (330) 483-4650 or request a quote online to learn more about how we can meet your specific heat treating needs with our expertise and advanced induction services.

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