Research On Deterioration Mechanism Of Steel Properties Under Corrosion Effect In Marine Environment

With the development of coastal engineering,offshore engineering and other marine businesses,improving the durability and safety of steel structures in the marine environment has important practical significance for improving the quality of projects and ensuring the safety of people.Studying the mechanism of deterioration of steel performance by corrosion-loading under marine environment is a method that can help solve the problem of durability and safety of steel structures in offshore environments.It is an effective method for analyzing and calculating the stress intensity of steel structures in offshore environments.This article takes Q345 B low carbon steel as the research object,comprehensively applies experimental research,theoretical analysis and other methods to systematically study the law of deterioration of steel surface degradation and the mechanical properties of steel under the effect of corrosion-load environment.Achievements:? Measuring the degradation characteristics of the specimen surface under different test conditions;Studying the law of change about the law of mass loss and the geometry with the changing of corrosive environment,load environment,and the coupling of the corrosion-load environment;Revealing the affect relations of surface degradation characteristics of steel structures under corrosion-loading.? Measuring the mechanical properties of the specimen in different test conditions;Obtaining the stress-strain curve of the specimen under different conditions;Studying the law of change about the yield strength,tensile strength,elongation and reduction of area with the changing of corrosive environment,load environment,or the coupling of the corrosion-load environment;Revealing the affect relations of the mechanical properties of the steel structure under corrosion-loading.? Correlating the surface degradation characteristics of the steel with the size of the cracked body and correlating the mechanical properties of the steel with the stress intensity factor based on the theory of fracture mechanics.Obtaining the dimension less stress of the steel material based on the test results of the steel under different combinations of corrosion and load conditions.The stress intensity factor solving equation was determined and the critical dimension of crack propagation was calculated.