Maschinenfabrik ALFING KESSLER GmbH

Induction hardening process on a crankshaft using an ALFING hardening machine

Surface treatment

Surface treatment is also one of the key skills at the automotive division. Outstanding engineering knowledge is boosted by decades of experience in the field of induction hardening. This is what led to the initial creation of our hardening machines in 1952. This product is in use at over 500 locations operated by engine manufacturers worldwide. Induction hardening enables targeted hardening of crankshafts, even in the fillet areas that are subject to high stresses.

Gas nitriding hardens the surface through the supply of nitrogen. In the nitrocarburising process, the crankshafts are treated with ammonia, nitrogen, carbon dioxide and cracked gas before being quenched in the oil bath. Deep rolling of the fillets, which is performed as a mechanical transformation procedure, also increases the fatigue strength. These multifaceted technologies enable us to meet almost all customer requirements in terms of increasing performance and reducing wear.

Quenching the bearing surfaces following induction hardening.

Following surface treatment by means of nitrocarburisation, the hardened crankshafts are quenched in the oil bath.

The application of compressive residual stress through cold-forming is an additional procedure for increasing the fatigue strength.