Galvanic Corrosion Behavior of Hub-bolt Joint of Magnesium Alloy

Aiming at the problem of galvanic corrosion of magnesium alloy hub in automotive industry, the physical model and mathematical model of galvanic corrosion for hub-bolt joint were built and the governing equations of galvanic corrosion were deduced. In combination with a moving mesh technique, the galvanic corrosion behavior of magnesium alloy hub-steel bolt joints in a sodium chloride solution was investigated by finite element method. And the influence law of counterbore depth and counterbore radius on the corrosion depth of hub was obtained. The correctness of the simulation method for the galvanic corrosion of magnesium alloy hub-steel bolt joint was verified by the full immersion test of the hub-bolt coupling pair. The results showed that with the increase of sinkhole depth, the average depth of corrosion increased first and then decreased. With the increase of sinkhole radius, the average depth of corrosion decreased, while the maximum depth of corrosion increased first and then remained approximately unchanged.