水利工程用管桩钢的组织与耐蚀性

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

对比研究了低碳钢(A)、单独添加0.18Cu(B)以及复合添加0.18Cu+0.18Cr(C)管桩钢的显微组织、力学性能和电化学性能。结果表明:B和C管桩钢的强度和断后伸长率都要明显高于A的,3种热轧态管桩钢的屈强比都低于0.7;3种热轧态管桩钢在液面上区域的腐蚀程度重于在液面下区域的,且在液-气界面处的腐蚀程度最重。单独添加0.18Cu和复合添加0.18Cu+0.18Cr后,管桩钢的腐蚀类型已经从局部点蚀转变为均匀腐蚀,含0.18Cu和0.18Cu+0.18Cr管桩钢的腐蚀速率明显低于低碳钢的;A和C管桩钢表面腐蚀产物都主要为α-FeOOH、β-FeOOH、γ-FeOOH和Fe_3O_4,且C管桩钢表面腐蚀产物中含有更多的Fe_3O_4;单独添加0.18Cu或者复合添加0.18Cu+0.18Cr都能提高管桩钢的耐蚀性,且C管桩钢具有相对更高的耐蚀性。

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 liqui＆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 Fe3 04, and more Fe3 04 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.