Studies On Fabrication And Hydrophobic Property Of Bionic Hydrophobic Surface On Pipeline Steel

Pipeline steel surface with bionic super-hydrophobic properties has a bright future in the field of pipeline transportation. Pipeline steel is mainly used to manufacture and process oil and gas pipelines. It will affect the service life of the pipelines if the inner surfaces of those pipes are corroded by the substances such as oil, gas and others. As the oil pipeline inside is easy to gather waxy organic matter which increases the friction between the fluid and pipeline, the fluid resistance will be increased by the friction that will increase the power consumption cost of oil transportation. As result, the problems of anti-corrosion and anti-fouling of pipelines and reducing the fluid resistance become more apparent. Through building biomimetic super-hydrophobic surfaces which is similar to a lotus leaf surface on the inner surface of the pipeline steel that enables the pipeline steel surface perform hydrophobic self-cleaning function can effectively solve the above problems.In this paper, a method combination with sandblasting and chemical etching is used to create super-hydrophobic properties on the surface of X52pipeline steel. The test shows that after chemical eroding by sandblasting, the surface of pipeline steel gets the composite structure of micron-sized pits, nanometer-sized steps and nanometer-sized pits. And with low-energy fluoride treatments, the pipeline steel with super-hydrophobic surface which at an angle of more than150°ith the water will be formed. Along with the increasing of the sandblasting time, the contact angles between water and the hydrophobic surface of pipeline steel increase at first and then decrease. And it also shows the same trend with etching time extension at different concentrations of hydrochloric acid etching solution. Following the criterion of the water contact angles, the optimal process parameters including the sandblasting time, the concentration of hydrochloric acid and the etching time are determined. The parameters have been put into use on pipeline steel surface to create a rough surface combination with15μm-20μm pits and100nm-150nm papilloma structure. Then with low-energy modification, producing a superhydrophobic surface which at an angle of156.4°with the water.There is a composite contact between water droplets and superhydrophobic surface of pipeline steel. The surface with micro-nanometer rough structure filled with air. Thus, water droplets locate in the composite interface of the matrix and air. The airs play a role of mattress, which results in the decrease of solid-liquid contact area and excellent hydrophobic properties.