Initial Corrosion Behavior Of Q235 Steel In Thin Fluid Film Of Simulated Medium

The initial corrosion behaviors of Q235 steel under thin liquid film in 1m mol/L NaCl, 10m mol/L Na₂CO₃ and 10m mol/L Na₂SO₄ were studied respectively. The relevance of the experimental parameters with the atmospheric parameters and contamination ions are studied by three methods that time of wetness (TOW) test, Electrochemical Noise (EN) and Inductive Resistance Probe (IRP), experimental parameters including TOW, noise resistance and corrosion rate and so on, atmospheric parameters including temperature, humidity, time of immersion(TOI) and so on.TOW of Q235 steel can be determined by observation measurement and EN analytical method, the result shows two methods have the very good relevance; the influence of different environmental parameters and pollutant ions to TOW by the rust was investigated based on the analysis of TOW of rusted and non rusted steel, the result shows the influence to the TOW by the rust in the NaCl solution is more obvious than the one in the Na₂CO₃ and Na₂SO₄.solution.The corrosion behaviors of Q235 steel in thin liquid film in different environment parameters and pollutant ions were determined by EN technique, the typical atlas of standard deviation of current in three medium under low humidity(RH≤70) and high humidity (RH≥80) can be obtained using the noise data by the time domain analysis, which can be simulated effectively the corrosion process of thin liquid film on the surface of Q235 steel in different atmospheric parameters; the corrosion rate in three mediums according to noise resistance analysis with the condition of low temperature-low humidity and high temperature-high humidity is different:VNa₂CO₃ < VNaCl 2SO₄.The corrosion process of Q235 steel in thin liquid film in different environmental parameters and pollutant ions was measured by IRP technology, the PLU data was analysed by Integration Filter Algorithm (IFA), the trend of corrosion rate which is get from PLU rate of change along with time in the same experimental parameter but different medium is: VNa₂CO₃ < VNaCl 2SO₄.The corrosion rates of Q235 steel which are analysed by three methods including standard deviation of current, noise resistance and IRP probe data in three medium have the very good relevance.