涂层开裂对几种热喷涂涂层抗蚀效果的影响

研究了涂层开裂对高速火焰喷涂Ni-Cr/Cr3C2、高速火焰喷涂Ni60B/WC、高速电弧喷涂Fe-Al/Cr3C2、高速电弧喷涂FeCrAl四种涂层抗蚀效果的影响.研究结果表明,涂层开裂导致不同涂层的抗蚀效果有不同程度的下降;基体暴露在外进而被腐蚀是抗蚀效果下降的主要原因;基体被暴露的面积不同是抗蚀效果下降程度不同的直接原因.和涂层开裂和涂层抗蚀效果的影响的研究有待于进一步深入.     

钢铁结构件长效防腐技术

钢铁结构件在大气环境中的腐蚀所造成的损失和破坏是巨大的。采用电弧和火焰喷涂技术在钢铁结构件表面喷涂一层或几层锌．铝或者锌一铝复合涂层，加上封闭技术，可以对钢铁基体起到长效(10－3０年以上)保护与防腐功能．本文简述了锌，     

锌—铝复合涂层在水工钢结构长效防腐中的应用技术

水工钢铁结构件在大气及水下环境中的腐蚀所造成的损失和破坏是巨大的。采用电弧和火焰喷涂在钢铁结构件表面喷涂一层或几层锌、铝或者锌－铝复合不作废支加上封闭技术,可以对钢铁基体起到长效１０－３０年以上）保护与防腐功能,本文简述了锌－铝复合涂层的防腐性能和特点,结合国内外有关现场考核实验数据和大量实例,较全面地介绍了热喷涂锌－铝复合涂层这一长效防腐技术及其广阔的应用前景。     

电弧喷涂防腐在污水处理钢制设备中的应用研究

采用电弧喷涂技术在Q235钢基体上制备了锌、铝防腐涂层样片,并用样片在城镇污水中进行了半年的腐蚀模拟试验。试验结果显示：环氧封闭处理的锌涂层与铝涂层表面几乎不发生变化,涂层与基体的结合力不变;而不经封闭处理的铝涂层样片产生白色析出物,锌涂层样片能起到阴极保护作用,但腐蚀速率较快。     

镁合金等离子喷涂Al/Al_2O_3涂层的耐腐蚀性能

采用等离子喷涂技术在AZ31镁合金表面制备Al/Al_2O_3复合涂层,测试了镁合金及表面喷涂有Al/Al_2O_3复合涂层的镁合金试样的极化曲线,研究了没有涂层、经封孔处理和未经封孔处理的喷涂有复合涂层的镁合金三种试样在浸泡腐蚀和5%NaCl盐雾腐蚀情况下的耐腐蚀性能及其腐蚀行为.结果表明,经封孔处理的Al/Al_2O_3复合涂层镁合金试样在上述腐蚀条件下的耐腐蚀性均优于镁合金和涂层未封孔处理的试样,在浸泡试验中未封孔处理的涂层试样比镁合金腐蚀更加严重,在盐雾试验中却优于镁合金.     

电弧喷涂铝涂层热扩散锌封孔技术

采用在电弧喷涂铝涂层表面喷涂一层锌然后进行整体热处理的方法,使低熔点锌扩散渗入铝涂层内部,达到封闭铝涂层孔隙的目的。采用金相分析、显微硬度分析、直流极化曲线测试以及电子探针分析技术,研究了不同热扩散处理参数下锌对铝涂层的封闭效果。结果显示,熔化的锌能够扩散渗入铝涂层的内部,当保温时间为30min时,锌的渗入深度可达150μm;保温时间延长至60min时,锌的渗入深度达200μm。经锌扩散封孔的铝涂层致密性显著增强,显微硬度升高,具有锌铝伪合金的优良性能。     

高速电弧喷涂Fe基合金陶瓷涂层的耐蚀性

为提高海洋设备的耐海水腐蚀性能,采用高速电弧喷涂技术在Q235钢基体上制备Fe基合金陶瓷涂层,并研究有机硅树脂封闭后的耐蚀性.分析了涂层的微观形貌、硬度及电化学性能.结果表明Fe基合金陶瓷涂层组织均匀、结构致密,孔隙率为6.8％,经有机硅封闭处理后涂层的开路电位及腐蚀电位提高,腐蚀电流降低,等效电阻增大,耐腐蚀性能大幅提高.     

超声激励封孔对等离子喷涂Al2O3—13％TiO2涂层耐腐蚀性能的影响

对于等离子喷涂Al2O3—13％TiO2陶瓷涂层,以有机硅透明树脂为封闭剂,分别采用常规浸渍封孔和超声波激励封孔方法在不同温度下进行封孔处理;采用10％HCl溶液浸泡试验和电化学腐蚀试验比较了封孔前后涂层的耐腐蚀性;应用光学显微镜、扫描电镜和能谱仪对腐蚀形貌及产物进行检测和分析。结果显示,封孔处理有效地降低了涂层孔隙率...     

Zn-Al-Mg-RE涂层自封闭特性在复合涂层中的作用机制

通过铜加速醋酸盐雾腐蚀试验,研究了自封闭特性在Zn-Al-Mg-RE高速电弧喷涂层与舰船涂料结合成防腐复合涂层中的作用.经过480h的试验,在基体上直接涂装涂料的试样表面的划痕里充满了铁锈,而中间喷有高速电弧喷涂层的试样表面划痕里只有少量的白锈.这说明在腐蚀环境中,Zn-Al-Mg-RE高速电弧喷涂层表面的微观孔隙能够被自身的腐蚀产物堵塞,生成的腐蚀产物非常致密,能够阻止缺陷处继续被腐蚀.从试验结果可知在复合涂层体系中,高速电弧喷涂层的自封闭特性起到了积极的作用.     

电弧及高速电弧喷涂FeCrAl涂层的微观性能研究

用相同的喷砂和喷涂工艺参数,分别在４５＾＃钢基体上制备了电弧喷涂与高速电弧喷涂ＦｅＣｒＡｌ涂层,用扫描电镜分析了它们的表面形貌,测试分析了两种涂层及各种基体在距涂层－基体界面不同距离上的显微硬度值,得到了电弧喷涂及高速电弧喷涂基体上的热影响区宽度,讨论了涂层的显微组织对其硬度的影响,并测试分析了涂层和基体的截面线波动系数。试验结果表明,高速电弧喷涂ＦｅＣｒＡｌ涂层比普通电弧喷涂ＦｅＣｒＡｌ涂人有更     

Long-term atmospheric corrosion properties of thermally sprayed Zn,Al and Zn–Al coatings exposed in a coastal area

The long-term atmospheric corrosion properties of thermally sprayed Zn, Al and Zn–Al coatings have been evaluated using an electrochemical impedance measurement and several analytical techniques. All the thermal-sprayed specimens with 100 μm coating thickness have protected the steel substrates. In case of the Zn–Al coating, the red rust was not observed regardless of the coating thickness. The corrosion products were identified by the XRD analysis. Preferential dissolution of zinc was observed on the Zn–Al coating by EPMA analysis. The electrochemical impedance results provided an insight about the surface structures of each thermally sprayed coating.     

火焰喷涂Al、Zn-Al涂层在舟山地区海洋环境的腐蚀行为

利用宏观腐蚀形貌分析、3D微观形貌分析、腐蚀产物XRD检测、电化学阻抗谱对火焰喷涂 Al和Zn-Al15%涂层在舟山站潮差区和飞溅区的腐蚀行为进行了探究,其结果显示：两种涂层经12 a海洋环境实验仍具有很好的保护性能,喷Al和Zn-Al涂层在潮差区腐蚀比飞溅区腐蚀严重;喷Al比Zn-Al涂层有更好的耐蚀性; EIS测试说明喷Al的阻抗值大于喷Zn-Al涂层,喷Al涂层的防护效果优于Zn-Al涂层。     

高速电弧喷涂锌涂层性能研究

使用高速电弧喷涂枪和普通电弧喷涂枪分别制备锌涂层。通过对结合强度、孔隙率、粒子尺寸和粒子飞行速度的测试表明,高速电弧喷涂比普通电弧喷涂的粒子尺寸减小,飞行速度提高,制备的锌涂层结合强度高,孔隙率低。对两种锌涂层进行的强化腐蚀试验表明,封孔处理后的高速喷涂锌涂层具有较好的抗腐蚀性能。     

Corrosion behaviors of arc spraying single and double layer coatings in simulated Dagang soil solution

Three kinds of single layer coatings of Zn, Zn15Al, 316L stainless steel and two kinds of double layer coatings with inner layer of Zn or Zn15Al and outer layer of 316L stainless steel by arc spraying were developed to protect the metal ends of prestressed high-strength concrete (PHC) pipe piles against soil corrosion. The corrosion behaviors of the coated Q235 steel samples in the simulated Dagang soil solution were investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and natural immersion tests. The results show that the corrosion of the matrix Q235 steel is effectively inhibited by Zn, Zn15Al, Zn+316L and Zn15Al+316L coatings. The corrosion rate value of Zn15Al coated samples is negative. The corrosion products on Zn and Zn15Al coated samples are compact and firm. The corrosion resistance indexes of both Zn and Zn15Al coated samples are improved significantly with corrosion time, and the latter are more outstanding than the former. But the corrosion resistance of 316L coated samples is decreased quickly with the increase in immersion time. When the coatings are sealed with epoxy resin, the corrosion resistance of the coatings will be enhanced significantly.     

电弧喷涂Zn-Al伪合金涂层耐腐蚀性能研究进展

通过在钢基体表面制备涂层可以很好地延长钢铁材料的服役时间,减少因腐蚀造成的重大事故和人员伤亡。相较于传统的纯Zn涂层、纯Al涂层以及Zn-Al合金涂层,Zn-Al伪合金涂层能够为基体材料提供长久有效的腐蚀防护,在钢铁材料的腐蚀防护中具有巨大的应用潜力。简述了Zn-Al伪合金涂层电弧喷涂制备工艺的特点;介绍了Zn、Al、Zn-Al合金及Zn-Al伪合金涂层在模拟海洋环境下的腐蚀防护原理;在此基础上从组分、喷涂工艺参数(喷涂距离、喷涂电流和喷涂电压)、元素掺杂(Mg、Si及Re)及后处理工艺(封孔、激光重熔)等角度,论述了其对Zn-Al伪合金涂层耐蚀性的影响;讨论了Zn-Al伪合金涂层防腐体系在桥梁、海洋钢结构件、地下运输管道中的应用现状;最后总结了目前研究工作中存在的挑战,提出了电弧喷涂Zn-Al伪合金涂层尚需深入研究的重点问题,为提高钢铁材料使用寿命提供了参考。     

Steel cathodic protection afforded by zinc, aluminium and zinc/aluminium alloy coatings in the atmosphere

Zinc has traditionally been the metallic material most widely used to protect steel against atmospheric corrosion due to its ability to afford cathodic protection to steel in all types of natural atmospheres. In recent decades, aluminium and zinc/aluminium alloy coatings have been used instead of zinc in certain atmospheric applications. Although these coatings present some advantages over zinc, they are not able to cathodically protect steel substrates in all types of natural atmospheres. The present paper assesses the cathodic protection afforded by Al (flame spraying), Al/13 Si (hot dipping), 55Al/Zn (hot dipping), Zn/15Al (flame spraying), Zn/5Al (hot dipping), Zn (hot dipping), Zn (discontinuous hot dipping) and Zn (electroplating). Aluminium and aluminium-rich alloy coatings (55%Al/Zn) provide cathodic protection to the steel substrate only in atmospheres that are highly contaminated with chloride ions (>100 mg Cl⁻ m⁻² day⁻¹) where these coatings become active.     

金属喷涂层在海水中的腐蚀研究

对火焰喷涂Zn、Al和Zn-Al涂层，在青岛进行海水腐蚀试验的结果表明，4年试验后，喷Al和喷Zn-Al涂层没有发生明显的腐蚀，喷Zn涂层腐蚀严重，150 μm厚的涂层寿命不足3年；盐雾-光照复合加速试验，结果表明，喷Al和喷Zn-Al涂层耐蚀性优良，而喷Zn涂层耐蚀性较差，同户外暴晒结果一致.     

Enhancement of the corrosion properties of cold sprayed Ti–6Al–4V coatings on mild steel via silica sealer

The pore formation associated with the cold spray process requires the development of an economical sealer to enhance the corrosion resistance of Ti–6Al–4V coatings on a mild steel substrate. Herein, a sound method is developed to seal pores in the cold sprayed Ti–6Al–4V coatings with silica sealer. Potentiodynamic polarization tests in 3.5 wt% sodium chloride electrolyte were employed to investigate the corrosion resistance of cold sprayed Ti–6Al–4V coatings fabricated at two standoff distances (30 and 70 mm) before and after the sealing process. The polarization resistance of cold sprayed Ti–6Al–4V coatings significantly increased by >80% after the sealing process. The electrochemical responses of cold sprayed Ti–6Al–4V were dependant on sealing the pores with agglomerated silica nanoparticles as observed by scanning electron microscopy and energy-dispersive X-ray analysis. The increase in polarization resistance makes the sealer an effective treatment for cold sprayed Ti–6Al–4V coatings used in marine environments and other engineering applications. This sophisticated sealing process can reduce the deposition cost by reducing the thickness of Ti–6Al–4V coatings and increasing their lifetime on metal components.     

海洋工程用钢表面喷涂Zn、Al和Zn-55%Al伪合金涂层的耐蚀性

热喷涂金属涂层是当前海洋环境下钢结构件防腐的首选方法,利用电弧喷涂技术在新型海洋工程结构用钢(Q345B钢)表面制备了Zn-55%Al伪合金热喷涂涂层,并与纯Zn涂层和纯Al涂层的耐蚀性进行了对比。结果表明:纯Zn涂层能提供较好的电化学阴极保护作用,但电化学性能欠佳;纯Al涂层表现出优良的电化学性能,但腐蚀后期产生点蚀;Zn-55%Al伪合金涂层具有更优越的耐蚀性和腐蚀防护性能。     

涂膜破坏后膜下镀锌钢板大气腐蚀扩展研究

    通过SEM和EDS研究了带有划痕的涂装镀锌钢板在海洋大气环境下暴露一年半后,划痕周围涂膜下腐蚀产物的扩展行为,并分别对电镀锌、热镀锌、电镀锌预磷化的材料进行了耐蚀性比较.结果表明,在划痕周围涂膜下镀层的耐蚀性与镀层制作工艺无关,而与镀层厚度有关;涂膜前的预磷化对耐蚀性产生了不利影响;虽然涂膜与镀锌层间发生分离,但对镀层的耐蚀性没有产生影响;海洋大气环境存在的氯容易富集在腐蚀产物的前端,而硫则较均匀的分布在整个腐蚀产物转化区.