疏浚用耐磨蚀钢耐磨蚀性能的研究

Erosion-corrosion Performance of New Developed Erosioncorrosion Resistant Steel for Dredging

采用热处理+微合金化工艺在兼顾耐腐蚀的基础上开发了一种450HBW的高硬度耐磨蚀钢,在实验室测试了其自腐蚀电位及海水浆体中的耐磨蚀性能,并与实际疏浚条件下的磨蚀实验结果作了对比,同时分析了磨蚀失重中各磨蚀分量的比例。结果表明,Cr的加入提高了基体的自腐蚀电位,抑制了腐蚀的发生,加上实验钢磨损性能的提高,促进了耐磨蚀性能的改善,实验室所采用的旋转型磨蚀测试方法能够真实反映材料在实际疏浚中的磨蚀性能,实验钢的耐磨蚀性能达到普通疏浚管道用钢Q235B的2倍,实验结果与疏浚现场的磨蚀对比实验相一致。海水疏浚中的磨蚀失重主要是磨损引起的,占磨蚀失重的比例达68%,腐蚀失重仅占1.6%,而腐蚀与磨损的交互作用失重超过30%。所以疏浚管道用耐磨蚀钢的研制应以提高耐磨损性能为主,同时抑制腐蚀的发生。

A new erosion-corrosion resistant steel with hardness of 450 HBW was developed via heat treatment and micro-alloying technology by taking its corrosion resistance into account. Then the free-corrosion potential and erosion-corrosion resistance of the steel in sea-water slurry was measured in comparison with those measured through the field-testing during dredging works. All the tested steel samples were characterized in terms of components of the mass loss due to erosion-corrosion. Experimental results indicate that the addition of Cr in steel is beneficial to reduce its free-corrosion potential i.e. to enhance the corrosion-resistance of the steel, in turn, its erosion-corrosion resistance was improved. The erosion-corrosion results measured by rotation method were consistent well with those acquired from practical applications. The weight loss is mainly caused by erosion, with a percentage of 68%. The corrosion alone contributed 1.6% percentage in erosion-corrosion weight loss, and the contribution of synergy of erosion and corrosion was more than 30%. So, the combination of higher erosion-resistance with appropriate lower corrosion-rate was a way to develop erosion-corrosion resistant steel for dredging pipes.