Induction Heat Treating
______________________________________________________________________________________________ Question of the Month: We use an induction process where we need to include physical barriers and/or a safety warning for people with medical devices such as metallic implants and cardiac pacemakers to stay a certain distance away. What is the required distance for people with such devices to stay away from induction heating […]
______________________________________________________________________________________________ Question of the Month: For a few years, we scan hardened relatively straight shafts using a 30 kHz machine. Our new component has a 4.8-mm radial step (sharp shoulder) that melted when we tried to scan harden. We heard that a single-shot inductor could reduce shoulder overheating and still provide sufficient hardening, so we […]
______________________________________________________________________________________________ Question of the Month: For quite a while after scan hardening, we experience low hardness readings (52-55 HRC) in areas where the diameter of our 1045 steel hollow shaft changes. We have consulted with induction heating specialists, but have not eliminated the problem. What causes soft spots at these locations and how we can […]
————————————————————————————————————————————————— Numerical computer modeling is a major factor in the successful design of induction heating systems. Induction heating is a complex combination of electromagnetics, heat transfer, and metallurgical phenomena involving many factors. Heat transfer and electromagnetics are nonlinear and closely interrelated because the physical properties of heated metals depend strongly on both temperature and magnetic […]
Induction hardening steel to austenitic temperatures can result in temper back, or annealing of adjacent areas of the material that have been hardened previously. This is particularly important in the induction hardening of crankshafts, camshafts, gears and critical components. This publication discusses above mentioned effect along with some other important features of induction hardening and […]
Induction surface (case) hardening of hollow shafts has unique features compared with hardening of solid shafts. With solid shafts, the core temperature typically does not rise significantly during heating. The relatively cold core compliments spray quenching by increasing the cooling intensity of shaft surface (cold-sink effect). By comparison, with hollow shafts, the cold-sink effect is […]
Some induction practitioners have heard about simultaneous dual frequency gear hardening. Coil current waveform comprises two appreciably different frequencies making effect of two single frequency inverters working on the same coil at the same time.