| The parameters of physical, mechanics and electrochemistry of soil polluted by Petroland Detergent were statistically analyzed from indoor simulation test. The change laws ofQ235steel macro, micro morphology of corrosion and corrosion rate were studied. Themultiple linear regression equations were established to describe the relationship between thecorrosion rate of Q235steel in polluted soil and the corrosive parameters of the soil on thebasis of the grey correlation method. The conclusion will provide reference for corrosionprotection of steel in practical engineering.Firstly, change laws of the physical, mechanics and electrochemistry properties of thepolluted soils with the content of Petrol and Detergent were statistically studied and get theconclusion: Plasticity index (the liquid limit, plastic limit and plasticity index) decrease withthe content increasing of Petrol, while increase with the content increasing of Detergent.The density, saturation and electrical resistivity increase with the content increasing ofPetrol, while decrease with the content increasing of Detergent. The compression coefficientdecrease and the compression modulus increase with the pressure increasing, meanwhile thevariation with the pollutants content increase was not obvious. The redox potential decreasewhile the corrosion potential increase as the content of pollutants increasing.Secondly, through the comparative analysis of the degree of impact on the soil pollutedby Petrol and Detergent was studied. It concluded that Petrol has greater influence on thedensity and corrosion potential than Detergent, and Detergent has greater influence on thewater content, saturation, electrical resistivity and redox potential than Petrol. Detergent’corrosion is greater than Petrol’ when the content is same overall. Thirdly, the macro and micro corrosion morphology of Q235steel were observated to getthe conclusion: The intensity of corrosion is much more obvious in the soils with highercontent of Petrol and age of pollutants, and more obvious firstly and less obvious lately withhigher content of Detergent. At the beginning period of the corrosion, corrosion begins partlyin area. As time went on, the corrosion was uniform at the late stage of the corrosion.Meanwhile the corrosion pits deepen gradually and corrosion products increase continuously.The corrosion pits of samples in soil polluted by Detergent are deeper than Petrol, and evenformed some penetrating holes.Fourthly, the corrosion rate of Q235steel increase as the content of Petrol and ageincreasing, while increase firstly and decrease lately as the content of Detergent increasing.Sequence of effects of the corrosion parameters of polluted soils by Petrol to corrosion rate ofQ235steel was determined according to grey correlation method—the electrical resistivity,redox potential and content of Petrol play the leading role on the corrosion of Q235steel.Moreover the density, corrosion rate and redox potential maintain a major role in pollutedsoils by Detergent.The multiple linear regression equations were established based on the relationshipbetween the corrosion rate of Q235steel and the corrosion parameters of the polluted soil. Itis proved that the equations could be used for calculating the corrosion rate of Q235steel insoil polluted by Petrol and Detergent. |
