Press quenching is often used to harden parts that are sensitive to distortion, but it is a difficult process to control due to the effects of tooling and the relatively large number of process parameters. In this paper, the authors show how they use finite element analysis to optimize the process and tooling design for a spiral bevel gear made of carburized 9310 steel. Several designs adaptations are assessed, one of which is shown to minimize radial shrinkage and taper distortion in the inner diameter of the bore.

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.