Structure and Corrosion Resistance of Pipe Pile Steel Used in Hydraulic Engineering

Microstructure, mechanical property and corrosion resistance of low carbon steel (A), adding 0.18Cu (B) and 0.18Cu+0.18Cr pipe pile steel (C) were comparatively studied. The results showed that the strength and elongation of sample B and C were significantly higher than that of sample A, the yield strength of 3 kinds of hot-rolled pipe pile steel was less than 0.7. The corrosion degree in the area of the hot-rolled pipe pile above the liquid surface was heavier than that in the area below the liquid surface, while the corrosion degree at the liquid-gas interface was the heaviest. After adding 0.18Cu and adding 0.18Cu+0.18Cr, the corrosion type of pipe pile steel had changed from localized pitting to uniform corrosion, and the corrosion rates of pile steels with 0.18Cu and 0.18Cu+0.18Cr were significantly lower than that of low carbon steel. The surface corrosion products of A and C steels are mainly composed of α-FeOOH, β-FeOOH, γ-FeOOH and Fe₃O₄, and more Fe₃O₄ was contained in the corrosion products of sample C. The corrosion resistance of pipe pile steel was improved by adding 0.18Cu or adding 0.18Cu+0.18Cr separately, and sample C had relatively higher corrosion resistance.