【作者】 周建龙；

【导师】 萧以德；

【作者基本信息】 机械科学研究院 ， 材料学， 2002， 硕士

【摘要】 举世瞩目的三峡工程是关系到我国21世纪国计民生的重大工程。它所涉及的许多建筑物及金属结构长期处于水／泥砂多相流动体系环境冲蚀磨损工况之下，破坏非常严重。针对三峡工程某些金属设备和结构，开展磨蚀与防护试验与研究是一项急需而又具有现实意义的工作。本工作进行了环氧耐磨涂料的配方设计，通过采用自制的圆筒型冲蚀磨损仪，从磨粒、材料性质、介质流速等多方面因素考虑，对国内外12种和自制6种环氧耐磨涂层进行了实验室加速冲蚀磨损试验，对高、中流速含泥砂水条件下环氧耐磨涂层的冲蚀磨损行为进行了研究。通过测定试样失重从而比较试样的抗冲蚀性及相对耐冲蚀性，并采用电子扫描显微镜显微分析方法，对环氧耐磨涂层的冲蚀机理进行了初步探讨，所得结论如下：(1) 许多涂层在各流速下均表现出不同的抗冲蚀性。这表明采用合适的有机耐磨涂层对钢材进行防护，可有效提高金属构件在水／泥砂多相流动体系中的抗冲蚀性能，延长其使用寿命。(2) 在不同磨料粒径冲蚀条件下，各种涂层的相对耐冲蚀性可能有一定差异；在同一条件冲蚀下的各种涂层，测得其抗冲耐磨数据相对稳定。随着磨料粒径的增加，涂层的相对耐冲蚀性下降。流速对冲蚀率的影响比磨料粒径的影响更大。另外，随着浓度的增大，各涂层间的相对耐冲蚀性有逐渐缩小的趋势，在低浓度下抗冲蚀较好的涂层有时在高浓度时不一定也同样抗冲蚀，表明涂层的抗冲蚀性是有条件的。(3) 随着时间的延长，涂层总的冲蚀磨损量逐渐增加，但单位时间内各涂层的冲蚀磨损量逐渐减小，冲蚀率趋于稳定。涂料中树脂本身并不耐磨蚀，起主要耐磨蚀作用的相成分是填料。另外，各种涂料添加剂的加入均对涂层的抗冲蚀性均有一定影响。(4) 环氧耐磨涂层的脆性冲蚀特征较为明显，冲蚀由显微切削机制和断裂机制等机制决定。由于磨料粒径的不同，冲蚀机制可能有所改变。更多还原

【Abstract】 The Three Gorge Project is a world-famous project. For many components,the erosion resistance of slurry water at medium or high speed is a dominant factor. To reduce the erosion rate of metals,organic protective coatings are widely used. In this work,Mass loss tests have been carried out on eighteen types of modified epoxy coating materials and six kinds of mild steels in slurry water. A modified rotating disk test rig was used to simulate silt abrasion and erosion with different quart sands at different velocities. The synthesis of six wear-resistant epoxy coatings was performed. The resistances of the various epoxy coatings to silt abrasion had been measured and compared under specified test conditions. On the one hand,the effects of curing agents,fillers,lubricant and coupling agents of the epoxy coatings had been discussed. On the other hand,the effects of quart sand contents,diameter of the quart sands and flow velocity on the erosion resistance of the epoxy coatings had been studied through mass loss test and SEM observation. Among the selected materials,the results are as follows:1. Almost all of the modified epoxy coatings show good wear-resistance at different speeds,which illustrates that it is effective to use modified epoxy coatings to protect steel. Therefore,the lifetime of metal is prolonged.2. Under the erosion conditions of different sand diameters,not all of the coatings have the same order;Under the same erosion conditions,the data of all the coatings are relatively stable. With the increase of erosion particle diameter,the relative wear-resistance of coatings decreases. Moreover,the effect of flow velocity is much greater than that of particle diameter. In addition,with the increase of concentration,the relative wear-resistance of coatings has a slow tendency of decrease.3. With time going,the total erosion masses of coatings increase gradually,but the erosion masses of coatings in one unit of time decrease gradually,and the erosion rate tends to be stable. The erosion rate of epoxy coatings mainly comesfrom resin matrix because the erosion-resistance of resin matrix is much lower than that of the fillers. Furthermore,all of the addictives added have some effects on erosion-resistance of the coatings.4. Pure epoxy coating shows typical brittle erosion behavior,and the erosion is determined by both micro-cutting mechanism and fracture mechanism. Owning to the differences of particle diameters,the erosion mechanism may be different.Author:Zhou Jianlong (Material Science) Directed by:Prof. Xiao Yide更多还原