Root crack I - Gear defects

Root crack I - Gear defects - Other defects

Figure 1: Root crack.

Defect name: Root crack
Record No.: 2050
Type of defect (Internal/Surface): Surface
Defect classification: Gear defects, other defects
Steel name: Steel
Steel composition in weight %: No data.
Note: Bending fatigue failure occurs over a long period of time. The initiation of crack takes place at the weakest point, normally at the root of the tooth or at the fillet where high stress concentration exists together with highest tensile stress from bending or from the surface defects as shown in Fig. 1. The crack slowly propagates over 80 to 90% of the life.
Reference: Not shown in this demonstration version.