The cable terminal will occasionally has such mechanical fault as flange and bolt breakage during the operation in the humid and hot coastal region

which poses a serious threat to safe operation of cable. For analyzing the breakage mechanism and stress characteristic of the bolt

the tensile properties

changes of chemical composition

metallographic microstructure and surface morphology of the broken bolt are analyzed in this paper firstly. Then

the stress-strain characteristics of the bolt in the cable terminal are analyzed by using the finite element method. The study shows that the chemical composition of the broken bolt does not comply with the standard requirement

the mechanical performance and corrosion resistance performance are significantly weak. The middle position of the screw in the operated cable terminal has great stress and deformation and is the vulnerable position of bolt. Therefore

under the influence of high stress and the coastal environment of high-temperature

high-humidity and high-salt fog

corrosion accelerates and racks are firstly generated on the surface of the middle part of the screw. Then cracks expand inward. At the same time

the action of electric field and current has accelerated partial corrosion of the bolt. Finally

the stress corrosion breakage of the bolt occurs in the middle of the screw. The study provides reference and suggestion for the design

type selection

operation and maintenance of the cable terminal.