Causes of wire rope fracture in oil fishing operation

The wire rope of an oil extraction truck suddenly broke during the oil extraction operation in an oil extraction plant. The fracture reasons of wire rope were studied by macroscopic observation, chemical composition analysis, metallographic examination, tensile test, whole rope breaking tensile test and scanning electron microscope analysis. The results show that there were a large number of wear and extrusion damage on the surface of steel wire rope, the fracture surface was characterized by shear failure and torsion-tensile fatigue failure, and the angle between the fracture surface crack and the axial direction was 45°. In the process of use, the initial cracks were initiated at the wear and extrusion of the steel wire surface. Under the action of torsion-tensile load, the loose twist structure of the steel wire rope was destroyed, resulting in stress concentration, which eventually led to the fracture of the steel wire rope.