Research On Protective Coating And Conductive Material In The Grounding Grid Corrosion Behavior In Red Soil

The topic for the grounding grid corrosion status of red soil were investigated in a certain area in the south to depths of soil sampling,0.8m substation as the medium,by temperature control moisture acceleration method commonly used materials of grounding grid Q235accelerated corrosion experiments and field experiments using buried,weight loss method and micro analysis to research on accelerated test piece and buried pieces of samples by law,it analyzes the effect and feasibility of indoor accelerated corrosion by electrochemical method,the effect of different p H value,water content,soil SO42-and Cl-content under the corrosion behavior of grid materials,at the same time the development of grounding grid corrosion prevention conductive coating,using epoxy resin as film-forming material,conductive graphite and carbon nanotubes as the conductive filler,studied the effect of various additives on the conductive coating filler,physicochemical properties and electrical properties.The main conclusions are as follows:Indoor accelerated corrosion test shows the Q235 under accelerated temperature for 65degrees,water rate is 20%,the indoor accelerated corrosion effect better,adopt moisture temperature control method to accelerate the corrosion,speed is up to 5.7 and the accelerated test of corrosion products and corrosion machine and field grounding materials in soil corrosion of highly consistent,and experimental compared both in the mechanism of the corrosion product and has great relevance.Indoor accelerated corrosion test pieces and buried the XRD analysis results show that,connected to the grounding grid corrosion products of iron oxidation products are mainly Fe₂O₃ and Fe OOH,both in the soil of the corrosion products and corrosion process,corrosion mechanism is more consistent.The corrosion products of indoor accelerated corrosion test tablets and buried tablets were found by EDS and SEM.The main elements of the corrosion products were Si,O,K,C,Fe,Al.K ion source in the soil,Si,C,some plasma may come from the dissolution of the material itself,but most should is the source element in the soil,and this topic take accelerated corrosion method with good reproducibility.With the water content increasing,Q235 corrosion current showed the trend of first increased and then decreased,when the moisture content of 20% of Q235 in soil corrosion rate reached the maximum.With the increasing of soil p H,Q235 corrosion current is decreasing.With soil SO₄^2-increasing,changed Q235 corrosion current.The adhesion of the conductive coating was greatly related to the addition of graphite,and the adhesion decreased with the increase of the graphite content.The hardness of the coating is also affected,with the increase of the graphite content,the hardness of the conductive coating decreases.With the increase of graphite content,the volume resistivity of the graphite/epoxy coating is decreased,and the volume resistivity of the graphite/epoxy coating is 10^-1?·m,when the amount is 35%.The influence of the doping of carbon nanotubes on the volume resistivity of carbon nanotubes is investigated.When the amount of carbon nanotube was 14%,the volume resistivity of the coating reached 10⁰?·m.With conductive composite filler add,the volume resistivity of the coating showed a declining trend,which with single filler add the influence trend on the volume resistivity of coating is consistent.Compared with single filler and composite filler added makes the volume resistivity of the coating decreased more obviously.This is because the packing of different sizes,each filling,improve the filling rate of conductive filler in the matrix.KH550 can improve coating adhesion.With the increase of the content of coupling agent,the surface morphology of the coating was gradually become smooth and shiny,illustrate the coupling agent in a certain extent influence the surface morphology of the coating.With the increase of dispersant,the volume resistivity of coating with continuously decreasing.A cathodic protection system for the protection of the grounding grid is designed by using solar energy as the external power supply.