Hardness test on crankshafts
Crankshafts have to withstand complex mechanical stresses and therefore meet high requirements in terms of strength, pressure or impact loads. In addition to the chemical composition of the materials, surface treatment also plays a decisive role. For example, the induction hardening process allows crankshafts to be specifically hardened even in the highly stressed radius areas.
o measure the quality of the surface treatment, a major crankshaft manufacturer uses hardness testing equipment from Hegewald & Peschke that has been specially developed for this application at various of its production sites. With the testing equipment, crankshafts can be tested over their complete diameter. Hardness measurement according to the Rockwell C method is performed perpendicular to the crankshaft's axis of rotation.
Based on the crankshaft size, the hardness test head is positioned according to the test requirement. The crankshaft is clamped via the built-in pneumatics. This significantly increases the reproducibility of the measurement. Depending on the scope of the test, up to 30 crankshafts can be tested per hour.
For the quality inspection of large crankshafts from 1.6 to 4 m in length, the crankshaft manufacturer also relies on a universal testing machine inspekt 300 kN from Hegewald & Peschke.