Influences of Carbon Content on Corrosion Behavior of Low-Alloy Steels inSimulated Tropical Marine Atmosphere Environment

The cyclic immersion corrosion tests of 0. 07C steel and 0. 09C steel were carried out in simulated high humid and hot marine atmospheric environment. Combined with microstructure observation, corrosion morphology observation and corrosion product analysis, the effect of C content on the corrosion behavior of the two low alloy steels was studied by electrochemical test. The results showed that compared with 0. 07C steel, the content of pearlite in 0. 09C steel was higher and the distribution was not uniform, which raised the pitting sensitivity of the material. The effect of C content on corrosion resistance was mainly reflected in the middle and late stages of corrosion. After 4 days of corrosion, the corrosion rate of 0. 07C steel was about 15% lower than that of 0. 09C steel. The self-corrosion potential of 0. 07C steel was higher, and it was easier to form a protective passivation film.