Failure Analysis on the Wheel Bolt of Light-Duty Vehicle Through Metallurgical Investigation

This paper contributes to know the root causes of wheel bolt failure using experimental methods by providing appropriate solutions concerning repair strategies and the mitigation of future failure for durable vehicle operation. The investigation was carried out on a damaged and new specimen for comparison purposes with the standard specification of the bolt. The analysis was conducted through fracture surface examination of visual observation, chemical composition, metallographic analysis, and mechanical hardness test. The experimental results revealed that the fracture surface of the damaged bolt showed fatigue beach mark characteristics that unintentionally can occur due to fatigue, and the microstructural examination exhibited a more amount of dark structure on the damaged specimen because of the increased carbon content in the bolt. Finally, it was concluded that the typical features of overloading and fatigue mechanism observed at the bolts are assessed as the likely probable root cause of failure in wheel bolts.