【作者】 易春龙；

【导师】 张永忠； 孙智；

【作者基本信息】 中国矿业大学 ， 机械设计及理论， 2009， 博士

【摘要】 随着我国经济社会的不断进步和交通工程建设节奏的加快,对钢桥梁的耐久性提出了更高的要求,高效施工设备和长效防腐涂层体系也正备受重视。本文设计和试验了高效多雾化电弧喷枪,解决了传统喷涂设备工效低和喷幅窄、且涂层附着力低、厚度不均匀和质量不稳定的难题;针对国内对电弧喷涂封闭涂层缺乏研究的现状,研制了电弧喷涂层纳米改性环氧封闭涂料,提出了二步法制备纳米封闭涂料的工艺方法,探讨了电弧喷涂层纳米改性环氧封闭涂料的封闭机理和耐蚀性机理;设计了电弧喷涂纳米封闭复合涂层体系,通过电弧喷涂阳极性金属涂层和纳米封闭有机涂层的协同作用,显著提高了复合涂层的耐蚀性和结合强度,具有涂层附着力高、防腐蚀寿命长、寿命周期成本低的特点,为钢桥梁的耐久性和安全性提供有力的技术保障,具有重要的工程应用价值。针对钢箱梁大平面喷涂施工对机械化高效喷涂的要求,通过多次雾化射流技术研究,研制了高效多雾化电弧喷枪,与机械化喷涂工装配套形成的高效多雾化电弧喷涂系统,与现在通用的普通电弧喷涂设备相比,喷涂电流提高1倍(达到700A)、喷涂速度提高2倍(达到78kg/h)、喷涂幅宽提高2倍(有效幅宽达140mm)、涂层附着力提高40%、涂层厚度分布更均匀、涂层质量更稳定。针对电弧喷涂层多孔隙的固有特性和高渗透性封闭涂料有效封孔的要求,研究了多种纳米氧化物粉体的表面改性和在环氧树脂涂料中的分散技术,提出了先制备多种纳米材料杂化的浓缩浆再制备纳米改性环氧封闭涂料的二步法工艺,制备了纳米改性环氧封闭涂料(发明专利公开号CN 1887992A),具有粘度低、渗透性好、封孔能力强、涂层附着力高、涂层致密、耐蚀性好等特点。通过试验研究分析了纳米改性封闭涂料对电弧喷涂层的双重封闭作用机理,用电化学阻抗谱(EIS)研究了电弧喷涂纳米封闭复合涂层的防腐蚀机理。纳米颗粒能改善封闭剂对基体的渗透性能,能充分渗透至电弧喷涂层孔隙内,涂层致密,与基体结合力提高,具有很好的物理隔离封闭作用。封闭涂料中的防锈颜料与电弧喷涂锌/铝金属发生化学反应,生成耐蚀的磷酸盐钝化膜,不仅更好地封闭了电弧喷涂层的孔隙,也进一步提高了复合涂层的结合力和耐蚀性。纳米材料的加入改善了涂层的电化学性能,对基体金属的腐蚀防护作用明显。针对钢桥梁的长寿命防腐要求,首次设计和应用了电弧喷涂纳米封闭复合涂层体系(CN101451243A),采用电弧喷涂金属防腐层和纳米封闭有机涂层的联合保护可起到最佳协同效应,显著提高复合涂层的耐蚀性和结合强度,具有涂层附着力高、防腐寿命长、寿命周期成本低的特点,在多座桥梁工程获得成功应用。更多还原

【Abstract】 With the progress of the economy and society of our country continuously and acceleration of construction pace in traffic engineering, the higher requirements of durability for steel bridges are put forward, efficient construction equipment and long-lasting anti-corrosion coatings system are also being focused upon.In this dissertation, an efficient multi-atomizing arc spraying gun is designed and tested to solve the problems facing by the traditional arc spraying equipment, such as low efficiency, narrow spraying width, low adhesion, uneven thickness and unstable quality of sprayed coating. For the status of lack of domestic research on the sealing coating for arc spraying coating, the formulation of nano-modified epoxy sealing paint is designed as arc spraying coating sealer, the two-step process method of preparation of nano-modified paint is proposed, the sealing and corrosion protection mechanism of arc spraying coating is discussed. The arc spraying nano-sealing composite coating system is firstly designed. Through the synergy action of arc spraying anode metal coatings and nano-sealing organic coatings, the corrosion resistance of the composite coating and its bonding strength are significantly increased, with the characteristics of high coating adhesion, long-life anti-corrosion and low life cycle cost. The composite coating system provided strong technical support for the durability and security of steel bridges, and had important engineering application value.According to the characteristics of large flat of steel box girder fitting for mechanized efficient arc spraying, and through the study of multi-atomizing spraying technology, the efficient multi-atomizing arc spraying gun is firstly developed, and supported with mechanized spraying apparatus to forming the efficient and multi- atomizing arc spraying system. Comparing with traditional arc spraying equipment, the newly developed multi-atomizing arc spraying system has achieved the following goals: the spray current is doubled (up to 700A), the spray rate increases two times (up to 78kg / h), spray width increases two times (effective width up to 140mm), coating adhesion increases 40%, coating thickness distribution is more uniform and coating quality is more stable.The arc spraying coating is porous inherently and needs to be effectively sealed by a high permeability sealing paint. So the nano-modified epoxy sealing paint is put forward to meet the requirements. The surface modification of variety of nano-oxide powders and dispersion technology in the epoxy resin paint are studied. The two-step process to prepare nano-modified epoxy sealing paint is advanced by preparing the nano-material concentrates firstly and then producing the nano-modified paint. The nano-modified epoxy sealing paint and its produce method are applied the patent right (Invention patent publication number: CN 1887992A). Nano-modified epoxy sealing paint has physical and chemical sealing dual role for the arc spraying coating with the advantages and characteristics of low viscosity, good permeability, strong sealing capability, high coating adhesion, compact coating structure and good corrosion resistance, etc. The two-step process method of preparing nano-modified paint brings upgrade of traditional protective paint industries, and provides a reasonable means of industrial protective paint production and change of paint production technology.The physical and chemical sealing dual role mechanism of nano-modified epoxy sealing paint for the arc spraying coating is analyzed by experimental research. Corrosion resistance mechanism of arc spraying nano-sealing composite coating is discussed by electrochemical impedance spectroscopy (EIS). Nano-particles can improve the permeability of sealer by fully penetrating into the porous of arc sprayed coating. The sealing coating is dense, and coating adhesion with substrate is increased, with a good physical isolation sealing effect. The sealer pigment could make chemical reaction with arc sprayed Zn/Al coating, and generating the phosphate passive film with good corrosion resistance. Not only the porous of arc spraying coating is better sealed, but also the adhesion and corrosion resistance of the composite coating is further enhanced. The electrochemical properties of the coating and corrosion protection for the substrate are improved by adding nano-materials to sealing paint.According to the requirements of long-life anti-corrosion and durability for steel bridge, the arc spraying nano-sealing composite coating system is firstly designed and applied the patent right (Invention patent publication number: CN 101451243A). Not only the best synergistic effect would be formed by the joint protection of arc spraying metal coating and organic nano-modified sealing coatings, but also the corrosion resistance and the bonding strength of composite coating system could be significantly improved. The composite coating system provides strong technical support for the durability and security of steel bridge by the advantages of high coating adhesion, long-life corrosion protection and low life cycle cost, and also be applied successfully on some large-scale steel bridges. There are very good actual engineering application value and important scientific significance.更多还原