8 Stories on How Computer Simulation Helped Companies to Improve Induction Heating in 2020

The year 2020 was tremendously challenging for businesses in the automotive and machinery industries, but some open-minded companies managed to become winners and increased efficiency incrementally. Adoption of computer-aided engineering (CAE), or so-called simulation, for tooling design and optimization of production processes like induction heating, pre-heating, and hardening is a good example of such winning strategies.

For a long time, CAE software has been perceived as a very expensive investment to be used in the corporate R&D centers only. A European startup CENOS has made induction heating process simulation accessible for every engineer with its new-generation simulation software for induction heating and hardening applications, which has made simulation easy, affordable and not limited to R&D centers only - now accessible to production plant and smaller manufacturing company engineers with no or little previous experience in simulation.

The software company CENOS managed to grow fast throughout this COVID-19 year and almost tripled its revenue in 2020. That proves the demand for easy-to-use simulation as a way to increase productivity and overall efficiency in the situation of pandemic constraints.

Here are 8 stories from CENOS simulation software users in 3 different continents, all enjoying tremendous benefits provided by the adoption of induction heating tooling design and process simulation: A. Production plants - induction heating equipment end-users (ThyssenKrupp Presta Schönebeck, GKN Driveline Celaya, Netzsch do Brasil and Volkswagen Group Services), B. Induction heating equipment manufacturers and service providers (GH Induction, SMS Elotherm), C. German 'Mittelstand' - small shops for induction heating design and tooling (COBES GmbH, Lötec GmbH).

A. Production plants - end-users of induction hardening technology

(1) ThyssenKrupp Presta Schönebeck saved 90% on tooling and 30% on energy

Marcus Hellriegel – an engineer at ThyssenKrupp Presta in Schönebeck (Elbe) near Magdeburg in Germany, managed to design a new induction coil for hardening of the ball track inside a ball nut (a steering system part) which reduced the tooling costs per part by 90% and energy consumed by 30%, which resulted in seven-digit savings for the company per year. Marcus was able to complete the new design just in a couple of months in a very cost-efficient way by using CENOS Induction Heating simulation software and 3D-printing technology.

The problem Marcus was trying to solve was a very short lifetime of the so-called hairpin-type coil used for hardening of the inner ball track. Thus, Marcus’ primary goal was to improve the coil design to achieve a longer lifetime and lower production costs. It took about 10 design iterations to come up with the new coil shape, which demonstrated excellent results in tests. Now, ThyssenKrupp is pending the patent for this brand new coil design. For this job, Marcus decided to use simulation software to test design candidates virtually and 3D print the final coil. Here are the economics behind this decision:

Thus, if things were done the traditional way by ordering conventionally manufactured coils from a supplier, 10 design & prototyping iterations would take more than a half-year (taking into account the time for design, tests and result analysis) and would cost around EUR 60,000 just for different coil design version trials. For such a sophisticated coil type, one could save time by ordering 3D printed coil prototypes from an additive manufacturing supplier but still it would take 3-4 months and cost around EUR 10,000.

Marcus decided to learn the simulation software to be able doing all design iterations by means of

the computer simulation and 3D-print the final design candidate for the real-life test. From all simulation software available in the market, Marcus chose CENOS because it is focused on induction heating and ensures unmatched speed of learning due to its straight-to-the-point interface for induction tasks. So, the new design of the coil was completed in a couple of months. The use of simulation unleashed the engineering talent of the designer allowing to test even the craziest ideas at no extra cost – everything was tested virtually on a PC and eventually fabricated with the help of 3D printing.

When the new coil was 3D-printed, it was time for the lab tests. It was surprising that the test demonstrated up to 30% of energy saving for the newly-designed coil compared to the old one. The reason for this dramatic increase of energy efficiency is due to the fact that the 3D-printed coil has no soldering joints. This particular inductor type, if conventionally manufactured, has up to 20 soldering joints – each joint increases overall coil resistance that results in a higher energy consumption. A 3D-printed coil on the contrary has zero solderings – thus, lower electric resistance.

While the main goal of the project was to create a new design for the coil that will not break so often, tremendous savings came from lowered production costs and increased energy efficiency of the coil. The coil efficiency was enabled by 3D-printing technology, and simulation software made the design process extremely efficient. That all, multiplied by the engineering talent of Marcus Hellriegel, led to an exceptional return on investment (ROI) for the combination of CENOS simulation software (EUR 7,800 per year) and the 3D-printed part (EUR 1,000 per coil) which resulted in saving 90% on tooling and 30% on energy costs.

(2) GKN Driveline Celaya increased overall equipment efficiency (OEE) for a CV joint hardening line by 9%

Kevin Tovar Estrada - a manufacturing engineer at GKN Driveline Celaya in Mexico, supervises induction hardening lines at the plant. He created a hardening “cookbook” – an algorithmic instruction for a machine operator to troubleshoot wrong hardening results. For example, the operator can change the gap size between a part and an inductor to correct the hardening profile when there is a slight change in part design, or some other parameters changes – quenching liquid, outside temperature, steel, etc. The operator makes an inspection of the hardening profile by cutting the part. If there is a deviation from the desired profile, he/she adjusts the parameters according to the “cookbook”, which ensures a reliable result with less scrap.

Simulation software helped Kevin to create such a cookbook 60% faster than in the traditional way with physical experiments. For a CV joint shaft hardening, the simulation approach also saved about 14 parts, which would be otherwise wasted. As a result, the production process runs with 60% less scrap.

Kevin did comparison tests to choose the right simulation software. CENOS - an induction heating specialized simulation software, demonstrated exceptionally good results: case preparation (setting of geometry and operational parameters) was 10 times faster than with other software, while calculation time was the same or faster. There was also a handy function that simplified the model by using constant magnetic permeability for faster calculation – the feature which was absent in other software. Total time for simulation analysis of a CV joint shaft hardening took 7.5 hours with CENOS.

To be sure about the results, Kevin compared the simulated hardening profile with the cross-section cut of the real part, the software had prediction accuracy of 93.8%. Then, Kevin redesigned the coil for CV joint hardening based on the simulation. He altered the position of flux concentrators and found a better design which eliminated local overheating. Old coil design failed and started leaking after 20,000 shots, while the redesigned coil is still running after 122,000 shots – more than five-fold improvement of the coil lifetime.

By summing all of the benefits of the simulation software adoption in the engineering routine of the plant, Kevin got a 9% increase of the overall equipment efficiency (OEE).

(3) Netzsch do Brasil reverse engineered hidden operational parameters of their induction machines for R&D

Klaus Heizinger - the head of research and development at hydraulic pump producer Netzsch do Brasil, is responsible for the production process R&D, efficient hardening of parts is an important part of his work. The company purchased an induction hardening machine a couple of years ago. Multiple things had changed since then - the design of the parts, the steel used, etc., as Netzsch was constantly working to improve their products and manufacturing processes. When trying to adjust the hardening process, Klaus and his colleagues were struggling to get satisfactory results. The main reason was very limited control over the hardening machine. “The operational interface gave us almost no quantitative data of the process”, explained Klaus. “For example, there are just three options for the frequency: high frequency, medium frequency, and low frequency, without any information of what are the absolute values of those frequencies. So, the engineers were wasting parts and time by doing numerous experiments, but still were struggling to get good results in many cases” Klaus admitted.

Then, Klaus decided to purchase a specialized induction heating simulation software with an idea to support reverse engineering of the machine settings for a better understanding of the process. That turned out to be a successful approach. “Now, we know much better what and how our machine can do”, proudly reported Klaus, “thus, we can work on the process improvements with confidence, experiment with new materials for parts. CENOS significantly improves R&D at our plants.”

(4) Volkswagen Group Services achieves fivefold productivity increase of power steering rack mounting production

Marcel Ruthmann - a young engineer at Volkswagen Group Services in Braunschweig, Germany, began using simulation to increase the efficiency of induction heating in the production processes of the company. While the majority of his successful projects will remain hidden for external observers, there is one worth a mention. By means of simulation with CENOS software and working together with Fabian Bauer - an engineer at Volkswagen in Wolfsburg, Marcel reduced the induction heating time for the mounting of the power steering rack about 5 times - from 9 seconds down to 2 seconds. Thus, the productivity of power steering parts manufacturing line is almost 5 times higher now