FAILURE ANALYSIS OF THE BROKEN BRAKE WHEEL HUB OF A BUS

Metallographic inspection was conducted to a brake hub broken in driving process, and the result shows that such factors as graphite slice being too big and in mass form, eutectic cell being too massive, hypo-surface substrate being ferrite and the proportion in the internal substrate of cast being too high as well as irregular degree of graphitization led to its breaking in its work state.