关键词: 钙处理, 桥梁钢, 工业-海洋大气, 湿热环境, 锈层

Abstract: The corrosion behavior of bridge steel in simulated hot and humid industrial-marine atmosphere was investigated by mass loss analysis, XRD, SEM, electrochemical methods and a wet/dry alternate immersion corrosion test using 0.1 mol•L^-1 NaCl+0.01 mol•L^-1 NaHSO₃ solutions. The corrosion depth (W) of experimental steels before and after calcium treatment versus time (t) curves showed a good agreement with the power function of W=Atⁿ. The corrosion products were mainly composed of amorphous phase and a small amount of crystals including α-FeOOH, β-FeOOH, γ-FeOOH and Fe₃O₄. Trace calcium could promote the formation of ferrite and strengthen the protective film on steel surface to prevent the rapid corrosion of bare steel. It could also refine the grain of steel structure and inhibit the crystal transformation of corrosion products, accordingly, refine the particles of corrosion products and reduce the defects in rust layer, and finally, improve the density of rust layer.