Fracture Analysis on Binding Bolt of Crane Turnplate

Binding bolts of the crane turnplate were fractured. By means of chemical composition analysis, macro and micro examination, the fracture reason was analyzed. The results showed that the fracture reason of bolt was found as fatigue fracture.The fatigue fracture was mainly caused by the defects in root of screw.After bolt loosening, the fracture was caused by the fatigue failure under the bending loads.