In this investigation, the electromagnetic effects of lightning on uncoated and PVC-coated high-steel metal buried pipes are numerically modelled and analyzed at varying earth surface depths of 1-2 m and varying PVC coating material thicknesses of 0.001-0.002 m. A typical lightning-injected current waveform was taken into consideration, and the corresponding return stroke current along the channel at different heights was thoroughly studied initially when it struck the earth's surface to validate the model. The study found that the density of induced current and field strength below the earth's surface is significantly impacted by the depth, with shallower depths having greater influence. The field strength and density of the induced current decrease with increasing depth. As seen, the insulation of PVC-coated metal buried pipe facilitates a higher density of induced current on the upper surface of the PVC coating, particularly for the finite earth surface conductivity (0.01 Sm-1). For finite earth surface conductivity (0.01 Sm-1) and a PVC-coated thickness of 0.0015 m at a fixed 0.105 m PVC coating diameter, the density of induced current at the mid-section of the PVC top surface reaches about 6696.37 Am-2. Additionally, the density of induced current at the mid-section of the pipe top surface was found to be about 14 Am-2, significantly lower than 5047.09 Am-2 for the uncoated metal buried pipe at the same depth. PVC-coated metal buried pipe has significantly lower induced currents than uncoated metal buried pipe at shallower depths. The proposed structure and reported analysis of PVC coating thickness may be beneficial in developing the mechanism of failure and designing a prevention plan for high-steel metal buried pipes from burns or physical damage.
