Induction is becoming an increasingly popular choice for heating steel billets prior to forging, due to its ability to create high heat-intensity quickly and within a billet, which leads to low process-cycle time (high productivity) with repeatable high quality, occupying minimal space on the shop floor. It is more energy-efficient and inherently more environmentally friendly than most other heat sources for steel billets.
Incorporating induction heating takes some planning and expertise, but it’s possible to optimize a progressive induction heating system for forging billets using CENOS Platform — a 3D-simulation software focused specifically on induction heating that uses open-source components and algorithms, making it affordable for small and medium-sized operations.
CENOS Platform is capable of simulating various types of induction heating for forging, including both static heating and progressive heating where the billet is moved through the coil with constant velocity.
The coil design portrayal also is without limitations: it’s possible to simulate single coil and multi-coil heating systems. Besides the coil, it is also possible to simulate any material and frequency.
The functional performance — CENOS Platform is a finite-element method-based, computer-aided engineering desktop software for 2D and 3D physical process simulation and computational modelling of induction heating, induction hardening, brazing, annealing and tempering of steel, aluminum, copper and other materials. It was designed to be as simple as possible to understand and to use, even for beginners.
The simulation process consists of three steps:
• Choosing the workpiece geometry (from built-in templates, or create your own CAD file);
• Defining induction heating parameters (frequency, voltage, time, etc.); and,
• Running 2D or 3D simulation of your choice.
At the end, results like temperature and magnetic field are displayed in 3D renderings, plots, and more. Apparent power, induced heat, and inductance are logged into an Excel file.
Comparing two heating systems — Let us consider simulation of progressive heating of the billet with two-stage and three-stage systems. The target for the simulation was to reach 1200°C ± 50°C.
To check each system, a user has to create setups for both of them, set physical parameters (material properties, frequency, current etc.), and start the simulation.
After the simulation is done, a user has access to different output variables:
• Temperature distribution
• Current density and Joule heat distribution
• Magnetic field lines
• Total, reactive and apparent power
• Inductance of the coil
• Coil current, voltage
• Et cetera
In our example of billet heating, it is possible to compare both cases and the output. It is evident how a three-stage system can decrease the power consumption and increase the production rate for this specific case.
It is also possible to plot the distribution of temperature, Joule heat, magnetic field, etc. A resulting temperature distribution in the billet across the radius is shown in Figure 1. As can be seen, better temperature homogeneity is obtained in the three-stage system.
Figure 2 shows how different systems lead to different temperature distribution. In a two-stage system, the temperature required for forging is reached with shorter coils, thus also with lower scanning speed. This leads to worse temperature uniformity and smaller production rates. On the other hand, the three-stage heater gradually increases the temperature of the billet and the resulting temperature difference between core and surface is smaller.
CENOS users are free to change all the input parameters and assemble the system of any number of stages as required for their process.
If it’s necessary to use the same system to scan shorter billets, where end-effects play a more significant role, it is possible to set up a simulation with a moving billet.
Making better decisions for set-up and planning — As demonstrated in the simulation example it is possible to compare two different systems and get results that make decisions easier, thus saving valuable company resources. The scope and variety of different simulations is unlimited, depending upon the problems that users want to solve. For example:
• Heating system design to optimize induction heating performance, improve product quality, and avoid unpleasant surprises related to subsurface overheating;
• The selection of power, frequency, and coil length in induction billet heating applications; or,
• Selection forging temperatures for plain carbon and alloy steels, to avoid possible damage by incipient melting or overheating.
Training requirements — There is a common misconception that simulation software requires specially educated (and well paid) simulation engineers, usually hired only for one kind of tasks — simulation. This is certainly true for sophisticated multi-physics simulation software packages.
CENOS 3D desktop software keeps its focus on induction heating and contains a variety of automated procedures so as to avoid any unnecessary functionality that might confuse inexperienced users. Using dedicated templates, a beginner can run his first induction simulation after just under 30 minutes, and become a pro user with any 3D geometry after one or two weeks of self-training, guided by CENOS engineers.
Moreover, CENOS offers webinars, customer support, an online forum and a rich documentation site to help engineers get started.
The required operating system is Microsoft Windows 7, 8 or 10. The required hardware is, at minimum Intel i5 processor (or similar), minimum 16GB of RAM, and 32GB of RAM is suggested. Graphics card performance does not play a big role; any standard GPU will cope with the visualization. Additionally the internet connection is required for software license verification only. An offline version can be purchased upon request.
Martins Vilums is the head of marketing for CENOS Platform, a desktop software for fully automated CAD processing for workpiece, coil, and flux concentrators, and presenting the simulated heating results in 3D. The software is available for a free 30-day trial, downloadable from www.cenos-platform.com