Corrosion Behavior of Three Kinds of Long-Size Steel Samples in Different Seawater Environments

Exposure tests were conducted in the marine environments of Qingdao, Zhoushan, Xiamen and Zhanjiang for three kinds of steel by means of electrical connection simulating long-size sample method. The corrosion behavior and law of three kinds of steel across total immersion zone, tidal zone, splash zone and atmosphere zone in these four test sites were studied. The results show that the corrosion rates of electrical connected long-size samples of three kinds of steel had two peak points and one low peak band. The two peak points were located in the total immersion zones and splash zones, and the low peak band was located in the tidal zones. Among the corrosion rate peaks measured in the splash zones, the one measured in the splash zone of Zhoushan station was the smallest. Among the corrosion rate peaks measured in the total immersion zones, the largest value was gotten in the total immersion zone of Xiamen station, and the values measured in the total immersion zones of other three stations were close. In the four test sites, the corrosion rate vs height curves of 09MnNb and 3C steels were basically the same in shape, and the corrosion rates at the same height was also close. The shape of corrosion rate vs height curve and the corrosion resistance of 10CrMoAl steel had obvious difference from those of 3C steel.