Härtezonenüberwachung an Planetenrandbolzen

Pins of planetary wheels are inductive hardended in the middle part whereas two millimeters of each end must remain in a non hardened soft microstructure state. Because 180 pins/min are produced only automatic testing system can be used to assure a 100% production control. The Barkhausen noise amplitude which is snesitive to annealed and hardened microstructure of the steel grade 100 Cr 6 is used. The probe system consists of four air coils and a Hall-probe. By evaluating the Barkhausen noise amplitudes a nondestructive in time hardness measurement can be performed.