Erosion Wear Mechanism And Evaluation Of Steel-structure Coating In Sandstorm

The central and the western region of Inner Mongolia is located in the northern borderof China, which covers a vast geographic area. There are six deserts in this area. Theclimate here is dry and windy, so sandstorm occurs frequently. There are a large number ofsteel-structures surrounding the deserts.The coating surface of the steel structure facilitieslong-term erosion by sandstorm so that the premature failure, make steel structure exposedrusted, results in the decrease of the safety and durability of structure. Therefore, analysisof steel structure surface mechanical properties of coating eroded by sandstorm, study onerosion mechanism of the steel-structure coating in sandstorm, and proposing a method ofevaluating erosion degree of the coating which has become academia and engineeringurgent research task. This thesis based on analyzing the sandstorm environmentalcharacteristics in the central and western region of Inner Mongolia and the physical andmechanical properties of the steel-structure coating materials, using the combined methodof theoretical analysis and experiment, analysis of the mechanical behavior and erosionmechanism of the steel-structure coating in sandstorm, and proposes a method ofevaluating erosion degree of the coating. Finally, analysis the similar of experimental dataand the actual working condition, making the results more realistic. This subject issupported by national natural science fund project (Grant no.11162011) and InnerMongolia of natural science fund project (Grant no.2009MS0706). Specific content asfollows:1. The thesis analyzes the sandstorm environmental characteristics in the central andthe western region of Inner Mongolia, and then determines sand erosion mechanicsparameters(sand particle characteristics, sand speed, and sand concentration).2. Using airflow jet with sand to conduct erosion experiment of the steel-structurecoating in sandstorm. Observed the erosion morphology of the coating at different erosioncondition by using the scanning electron microscopy and analyzed the mechanicalbehavior and erosion mechanisms. Results show that the coating appears the micro cuttingfurrows along the sand flow direction at low erosion angle, and with the angle increase to90°, the coating appears a vertical impact craters.3. Study on erosion mass loss relation with sand erosion mechanics parameters. Applying electronic balance to measure the weight of specimens before and after theexperiment, the result shows that the erosion mass-loss of the coating is up to maximumwhen the erosion-angle is45°,showed between plastic material and brittle materialerosion wear characteristics; The erosion mass-loss of the coating is increasing with theincreased erosion-speed; At a low sand dose, the mass-loss of coating increasing with theincreased sand dose, while at a high sand dose, the result is the opposite.4. The thesis proposes an evaluation method and the corresponding evaluationformula to evaluate the erosion degree of the steel-structure coating. The thesis alsocompares the calculating results with the test results, and verifies the feasibility andreliability of the evaluation formula.5. Using the similarity theory, the experimental results and the actual workingcondition were compared and analyzed, the study result show that under the condition ofthe highest concentration and maximum speed in this experiment, the erosion wear result isequivalent to suffer erosion wear from5.5months to7years in real sandstormconcentration areas of the central and the western region of Inner Mongolia.