This presentation explores a proven and cost-effective induction technology designed for contour hardening of bevel, hypoid, and pinion gears, as well as gear-like components with complex geometries, using inexpensive steels. Developed specifically to replace the carburizing process, this unique technology offers significant advantages. The presentation includes case studies that demonstrate the chemical composition of the steels used, the achieved hardness patterns, and the microstructure of the hardened area, transition zone, and core of the workpiece. The technology’s uniqueness lies not only in its ability to induction contour harden complex-geometry parts but also in its capacity to produce fine-grained martensitic structures (with typical grain sizes ranging from 8 to 11) and substantial compressive residual surface stresses (up to 600 MPa, or 85 ksi). These features dramatically enhance the mechanical properties of induction-hardened components.

In the last decade, when discussing subjects related to a computer modeling of induction heating, the word “usefulness” has been replaced by the word “necessity”. Modern computer simulation is capable of effectively simulating electromagnetic and thermal phenomena for many processes, including those that involve electromagnetic induction. Combination of a sophisticated engineering background with advanced process simulation software provides to induction heating professionals the unique ability to analyze, in few hours, complex technological processes. It offers the ability to predict how different, interrelated and non-linear factors may impact the transitional and final thermal conditions and what must be accomplished to improve process effectiveness, determine the most appropriate process recipes and serves as a comfort factor when designing new systems.

Induction surface hardening is a widely used manufacturing process in order to improve the mechanical properties of components. However, better process understanding as well as process development requires numerical modeling. The modeling itself depends on the input data regarding the process and the material behavior. Data acquisition is a rather difficult task due to very short process times, as seen in contour hardening of gears. The paper will give an overview over critical aspects regarding input data and their acquisitions as well as a comparison between experiments and simulation in order give a better understanding for improving the modeling.

In recent years, gear manufacturers have obtained comprehensive understanding about how technology can be used to produce quality gears. The application of this knowledge has resulted in gears that are quieter, lighter, and lower cost, and have an increased load-carrying capacity to handle higher speeds and torques while generating a minimum amount of heat, dramatically reducing distortion and requiring minimum or no post grinding.

Simulation of stresses during heat treating relates usually to furnace heating. Induction heating provides very different evolution of temperature in the part and therefore different stresses. This may be positive for service properties or negative, reducing component strength or even causing cracks. A method of coupled simulation between electromagnetic, thermal, structural, stress and deformation phenomena during induction tube hardening is described. Commercial software package ELTA is used to calculate the power density distribution in the load resulting from the induction heating process. The program DANTE is used to predict temperature distribution, phase transformations, stress state and deformation during heating and quenching. Analysis of stress and deformation evolution was made on a simple case of induction hardening of external (1st case) and internal (2nd case) surfaces of a thick-walled tubular body.