Failure Analysis on Cracking of Tyre Rims

Batch cracking of tyre rims of a company occured after service for about 15 days, and the cracking reason was analyzed by means of macroscopic inspection, chemical compositions analysis, mechanical properties testing, metallographic examination and fracture analysis. The results show that the failure of this batch of tyre rims was early fatigue cracking. The rim of the tyre rims presented machining marks at the fusion line, which resulted in notch stress concentration. At the same time, the inadequate weld at the crack source decreased the fatigue strength, fastened the expansion of the fatigue cracks, and eventually led to the early fatigue cracking of the tyre rims.