| At present, the method which appraise the anti-corrode performance of vessel steel is loss weight in natural seawater. The measurement's merit is experiment condition's reality, operation simple and result credibility. However, there are many shortages in the measurement. For example, the periods of experiment are very long, usually, the shortest experiment periods are one year; the circumstance factors are out of control; consequential the recurrence is bad; the risk caused by losing sample in the process of experiment is high. All shortages are mostly issues which restrict the use of new material, new craftwork. This paper used unconventional way, by the addition of H2O2 enhanced the depolarization of the way agents cathode depolarization, simulate and accelerate the corrosion of vessel steel. The correlation of the indoor and outdoor tests was evaluated from the test simulation, acceleration and reproducibility. The simulated acceleration mechanism and main factors was analyzed and the test method of simulation acceleration under marine immersion was founded. Major work and conclusions are as follows.Corrosion behavior of vessel steel 921A was studied in the sea water, seawater +0.01mol/L H2O2, seawater +0.01mol/L Na2S2O8 and seawater +0.01mol/L KC104. The results show that, the corrosion characteristics of 921A were similar in the sea water, seawater +0.01mol/L H2O2, seawater +0.01mol/L Na2S2O8 and seawater +0.01mol/L KClO4. H2O2, Na2S2O8 and KClO4 can accelerate 921A marine corrosion. Accelerated rate of Na2S2O8, H2O2, KClO4 were 15,2.8 and 2.5, respectively.The corrosion image of 921A steel were ulcer-like and corrosion products of 921A steel containsα-Fe2O3,γ-FeOOH and Fe3O4 in seawater containing 0.01mol/L H2O2, which is similar with marine corrosion. However, corrosion behavior of 921A steel between in the sea water and the sea water containing 0.01mol/L Na2S2O8. KClO4 acidic the solution. H2O2 as depolarizing agent most appropriate to add water to simulate the accelerated 921A steel in sea water immersion zone corrosion.Corrosion behavior of 945,921A,907A, E36 and Q235 steel was studied in the sea water exposure tests and simulation acceleration tests. The simulation, acceleration and reproducibility of simulation acceleration test were investigated. The results show that vessel steel of natural seawater exposure test and accelerated laboratory simulation test, the corrosion image, surface composition and structure of the corrosion product, the corrosion rate decreases with the immersion time.Vessel steel 921A, E36 and Q235 in the sea, seawater +0.01mol/L H2O2 and water +0.05mol/L H2O2 have been investigated. The results show that Corrosion potential decreases about rapidly in 24h, then Stochastic Volatility, and stabilizes after 400h between -0.63-0.68V. The polarization resistance first decreases and then increases with vessel steel 921A, E36, and Q235 immersed in the sea, sea water +0.01mol/L H2O2 and water+0.05 mol/L H2O2 for 2 weeks respectively. With the immersion time, corrosion products covered the surface to block the oxygen diffusion, and the polarization resistance increases to reduce metal corrosion. After 2 weeks, stable rust layer formed on the surface in the sample leads to stable the polarization resistance. After 7 weeks of immersion, the accumulation of a large number of corrosion products in the metal surface, which produce the pseudo-capacitance and interfere with the determination of polarization resistance.Analysis of low-alloy steel in seawater immersion and indoor simulation accelerate mechanism, the results show that:water immersion zone, low-alloy steel on the oxygen reduction reaction at the same time two electrons and four-electron reduction reaction, the reaction electron number 2.57. H2O2 as intermediate products added in seawater only accelerate the cathodic reduction. Thus it accelerate the low steel corrosion rate did not change the corrosion mechanism.The impact of simulation acceleration test the speedup of the main factors was investigated. The results showed that:how ensure that the Constant of H2O2 is important; not cause cavitation, erosion-corrosion of the premise, the stirring effect can accelerate vessel steel corrosion. The method can serve as a test method for laboratory simulation acceleration under seawater immersion, which is executed that the seawater with 0.8mol/L H2O2, the temperature of 70℃,the air filled, and weekly changed was selected as the test solution.
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