Research On Galvanic Corrosion Mechanism Of Q235 Steel In Acid Red Soils

With the development of science and technology, the corrosion protection of substation equipment gets more and more attention, and the corrosion protection of underground equipment is more and more concerned. But the grounding structure is complex, two or more than two kinds of different potential metals are coupled, and easily grounding body caused by galvanic corrosion damage. Shocking galvanic corrosion of grounding body damage, so the galvanic corrosion of grounding body must face and solve.This paper selects the typical Jiangxi acid soil as the experimental medium, selection of metal Q235 steel and copper used as grounding of galvanic effects of temperature, humidity, and resistance reducing agent and the influence of pH value on the galvanic corrosion, galvanic corrosion and mechanism.The results show that the corrosion of Q235 carbon steel mainly affects the soil temperature, the higher the temperature is, the more serious the galvanic corrosion of Q235 carbon steel. The main effect of humidity on the corrosion of Q235 carbon steel, carbon steel in the water content of 10% of the corrosion environment is mainly localized corrosion, and in the 20% and 30% water content of the soil is unifo r m corrosion. The corrosion products of Q235 steel and copper coupled is mainly Fe3O4.Galvanic corrosion of Q235 carbon steel in soil loss from two aspects, one is the corrosion effect of carbon steel, on the other hand is the effect of galvanic corrosion of the steel- copper thermocouple. The galvanic corrosion effect ? increased with the soil moisture decreased.Chemical resistance reduction agent is good, greatly enhance the copper steel on the galvanic current galvanic. Resistance reducing agent can effectively inhibit the corrosion behavior of Q235 carbon steel in the condition of low water content, but in the case of relatively high water content, it will play a role in promoting the corrosion of carbon steel.With the simulation of soil pH value of the solution is reduced, the Eg value of the galvanic potential decreases, thermodynamic tendency corrosion more samples more susceptible to corrosion, the corrosion rate is faster. When the pH value is low, the corrosion of Q235 carbon steel is mainly controlled by the activation reaction, and the self corrosion current increases with the decrease of pH value. When pH is high, impedancespectroscopy capacitive reactance arc with large radius, the corrosion of the metal is poor.