Induction hardening uses an alternating electromagnetic field to heat the surface of a conductive steel component very rapidly, usually followed by immediate quenching. The process hardens only the heated zone, producing a martensitic case while preserving a tougher core.
Because heating is rapid and localized, induction hardening is well-suited for the selective treatment of journals, splines, gear teeth, and wear tracks.
Scan hardening extends this concept by moving the coil relative to the part, allowing long surfaces to be hardened continuously.
At Braddock, induction processing would be used when precise local hardening, short cycle time, and controlled hardened patterns are required.
Induction hardening is common on components with specific wear surfaces rather than full-part hardening needs.
Depth of heat depends on frequency, power density, coupling, scan speed, and material response. Higher frequencies heat more shallowly; lower frequencies penetrate more deeply. Once the target surface reaches austenitizing temperature, quenching converts the heated layer to martensite.
Part geometry and coil design strongly influence uniformity. Corners, shoulders, changes in section, and interrupted surfaces can all affect the heating pattern.
Prior core hardness and material chemistry also influence final hardness and depth. Braddock would control frequency, power, coil design, scan rate, and quench delivery to achieve the required case pattern, depth, and hardness without overheating or soft spots.
