Mechanism of protective film formation during CO_2 corrosion of X65 pipeline steel

Electrochemical techniques, X-ray diffraction （XRD）, and scanning electron microscopy （SEM） were applied to study the corrosion behaviors of X65 steel in static solution with carbon dioxide （CO2） at 65℃. The results show that iron carbonate （FeCO3） deposits on the steel surface as a corrosion product scale. This iron carbonate scale acts as a barrier to CO2 corrosion, and can reduce the general corrosion rate. The protection ability of the scale is closely related to the scale morphological characteristics.

Laser Protection with VO_2 Film

This paper presents the principle,properties,advantage and disadvantage,associated problems and trend of laser protection with VO 2 film for infrared detectors in the range of 3～5μm and 8～12μm regions and suggests VO 2 film is a potential protection material for infrared detectors.

Introduction to Enhanced Protective Film Systems

An explosive blast mitigation alternative has increased the safety of structures by using " catcher" systems. These systems " catch" or repel the failure of the window or in-fill wall pro-tecting life and property from ballistic shards or fragments. They can be designed to be stand-alone in new construction and structural retrofits or used to augment structural hardening tech-niques. Cables, fabrics, and thin gauge sheet steel are examples of catcher systems used in the past. A new and evolving category of catcher systems are based on polymeric materials that can be used for both wall and window upgrades. These products are a proven blast mitigation concept and K&C Protective Technologies Pte Ltd (KCPT) together with Sherwin-Williams(SW) use KCPT′s blast engineering capacity and SW′s material engineering principles to create engineered systems for even greater in-use performance.

Corrosion protection properties of vanadium films formed on zinc surfaces

Vanadium films were prepared on zinc surfaces by using a solution containing vanadate. Corrosion protection properties of vanadium-treated （V-treated）, chromium-treated （Cr-treated）, and untreated zinc surfaces in contact with a 3.5 wt.% NaC1 solution were studied using potentiodynamic polarization, electrochemical impedance spectroscopy （EIS）, and neutral salt spray （NSS） tests. According to these results, the V-treated layer significantly improved the corrosion resistance of zinc surfaces. In comparison with the Cr-treated layer, the V-treated layer exhibited a better corrosion resistance. The composition of the V-treated layer was studied using X-ray photoelectron spectroscopy （XPS）. XPS measurements indicated that the vanadium layer formed on zinc surfaces and the vanadium-rich coating was a hydrated oxide with a composition of V2O5, VO2, and its hydrates such as V2O5.nH2O and VO（OH）2.

An Analysis of the Influence of Protective Films on the Inner Surfaces of CCPP Headers and Steam Pipelines on Their Thermal Stress State

At present, the main attention of researchers is paid to the deterioration of heat transfer when heating the outer surface of the pipe with the liquid or steam, flowing inside it, in the presence of films or deposits on its inner surface. However, when pipe is heating by heat carrier medium, flowing inside it, film on the inner pipe surface serve a dual protective function, protecting the pipe from corrosion and reducing its thermal stress. The article represents the results of the computational analysis of protective films influence on the thermal stressed state of headers and steam pipelines of combined-cycle power plants (CCPP) heat-recovery steam generators at different transient operating conditions particularly at startups from different initial temperature states and thermal shock. It is shown that protective films have a significant influence on the stresses magnitude and damage accumulation mainly for great temperature disturbances (for thermal shock). Calculations were carried out at various thicknesses of films and assuming that their thermal conductivity less than thermal conductivity of the steam pipelines metal.

Protective Properties of High Temperature Oxide Films on Ni-based Superalloys in 3.5% NaCl Solution

The electrochemical behaviors of high temperature oxide film formed on the sputtered microcrystalline coating of M38 alloy （mc-M38） were investigated by potentiodynamic and electrochemical impedance spectroscopy （EIS） techniques in 3.5% NaCl solution. Mott-Schottky analysis was used to study the semi-conductive properties of the surface oxide. The results of the capacitance measurements showed that the oxide films on both the coating and the cast alloy were p-type semiconducting characteristics. Both the carrier density （Na）and the flat band potential （Efb） were obviously frequency-dependent, and the optimal frequency range was from 1000 to 1500 Hz. The oxidized coating exhibited higher protectivity than the oxidized cast alloy due to the lower carrier density compared with that of the oxidized cast alloy. The EIS data of the long-term immersing tests suggested that the oxide film served as an inner-barrier layer against chloride ions. The penetration of the aggressive ions into the surface oxide resulted in the decreased polarization resistance as a function of the immersion time.

Failure Behaviors and Mechanisms of High-Ohmic Resistors Protected by PF/EP Paint in Heat and Humid Environment

Phenolic formaldehyde(PF)and epoxy(EP)resins are commonly used in electronic packaging. In this paper, high-ohmic resistors(2.2 M?, ±0.5%,)with Cr-Si film were coated by PF/EP paint, and the resulting coated resistors were used for heat and humid(HH)experiments. The experimental results show that the corrosion of bandlike resistive films is selective and isotropic, and that the corrosion spots in resistive films all form along grooves and extend in the same direction. It is revealed that OH^- ions are generated due to the electrochemical reactions of resistive film in HH experiments, so a NaOH aqueous solution with pH about 10 was used to study the effects of absorbed water and OH^- ions on PF/EP polymer film. The results indicates that the color of some part on PF/EP polymer film changes due to corrosion, and that the corrosion part of the polymer film is easy to be peeled off. It can be inferred that OH^- ions generated in HH experiments may play a catalytic role in the chemical reactions between polymer film and the absorbed water, which accelerates the degradation of PF/EP protection film for a resistor.

Magnetic field enhanced radio frequency ion source and its application for Si-incorporation diamond-like carbon film preparation

Various ion sources are key components to prepare functional coatings,such as diamond-like carbon(DLC)films.In this article,we present our trying of surface modification on basis of Si-incorporation diamond-like carbon(Si-DLC)produced by a magnetic field enhanced radio frequency ion source,which is established to get high density plasma with the help of magnetic field.Under proper deposition process,a contact angle of 111°hydrophobic surface was achieved without any surface patterning,where nanostructure SiC grains appeared within the amorphous microstructure.The surface property was influenced by ion flow parameters as well as the resultant surface microstructure.The magnetic field enhanced radio frequency ion source developed in this paper was useful for protective film applications.

QUANTUM-CHEMICAL MODIFICATIONS OF SURFACE:NEW METHODS FOR PROTECTING MATERIALS FROM CORROSION

A new method of corrosion-resistant coating of technical iron is presented. Processing by vibrationally excited hydrogen molecules of the iron surface covered with oxide film of α-Fe2 03 results in modification of surface by creating a film of amorphous iron on it. The presence of iron films with crystalline and amorphous phases, having the different Fermi levels, leads to formation of potential differences between them. This potential difference is opposite to the external electric field, resulting in decrease of anode current and increase of corrosion resistance.

Surface Analysis of Carbon Steel Protected from Corrosion by a New Ternary Inhibitor Formulation Containing Phosphonated Glycine, Zn²⁺and Citrate

Studies on surface analysis of carbon steel protected from corrosion in low chloride and nearly neutral aqueous environment by a synergistic mixture containing N,N-bis(phosphonomethyl) glycine (BPMG), zinc ions and citrate ions are presented. The effect of addition of citrate to the binary system, BPMG-Zn2+, is quite significant and is well explored through various studies. The surface protective nature is maintained in the pH range 5 - 9. Potentiodynamic polarization studies inferred that the ternary inhibitor is a mixed inhibitor. Impedance studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of carbon steel in the chosen environment. X-ray photoelectron spectroscopic (XPS) analysis of the surface film showed the presence of the elements namely iron, phosphorus, nitrogen, carbon, oxygen and zinc. Deconvolution spectra of these elements in the surface film inferred the presence of oxides/hydroxides of iron(III), Zn(OH)2 and [Fe(III), Zn(II)-BPMG-citrate] heteropolynuclear multiligand complex. This inference is further supported by the reflection absorption Fourier transform infrared spectrum of the surface film. Analysis by scanning electron microscopy (SEM) is presented for both the corroded and protected metal surfaces. Based on all these results, a plausible mechanism of corrosion inhibition is proposed.

TEMPERATURE EFFECT ON OXIDATION PROTECTION LIFE OF MULTI-LAYER COATING FOR C/C COMPOSITES

A multi-layer coating for carbon-carbon composites with a Si-W outer layer,a SiC barrier layer and a SiC transition layer is prepared by the combination of siliconiza-tion, CVD and liquid reaction method. The effect of temperature on the oxidation protec-tion life from 1600 to 17OOC is investigated. The thickness of the oxide film on thecoating surface is measured through SEM and EMPA. A concept of critical oxide filmthickness and a critical oxidation protection time is put forward, and, based on it, the re-lation of the critical time with temperature is analyzed. The re8ults show that the relationof the critical oxidation protection time with temperature found by the experiments is fullyidentical with that calcu1ated based on the critical thickness- The physical significance andthe effect factors of the critical oxide film thickness are discussed.

单宁酸-铜改性聚丙烯酸酯文物保护材料的制备及其性能研究

以单宁酸和硫酸铜为原料,采用水热法成功地合成了单宁酸-铜(CuTA)纳米片,同时通过简单共混法将CuTA添加到B72中,制备出单宁酸-铜/聚丙烯酸酯文物保护用复合材料.采用XRD、SEM等测试方法对CuTA纳米片的物相及表面形貌进行分析,利用X-Rite测色配色系统、静态视频光学接触角测试仪、紫外-可见分光光度计等对单宁酸-铜/聚丙烯酸酯复合材料的色差、接触角以及透光率进行测试.结果表明:当单宁酸与硫酸铜的物质的量比为1∶3时,可以生成稳定的CuTA纳米片,其对大肠杆菌和金色葡萄球菌的抗菌率分别为93.5%和98.7%;添加2 wt%CuTA纳米片所制备的复合材料对细菌生长有明显抑制作用,其抗菌率可达97.64%,同时复合材料的疏水性也明显提高,接触角可达87.7°;CuTA纳米片的加入可提高复合材料的紫外屏蔽作用,对复合材料的色差及可见光的透过率无明显影响.

An Analysis of Americans＇ Environment Protection Consciousness in the Movie The Day after Tomorrow

The Day after Tomorrow is a story about climate change,which was caused by greenhouse effect,and the world was pushed to another ice age.Based on the disaster movie The Day after Tomorrow,this paper is composed of three parts.The first part deals with the introduction of the film and environment protection consciousness.The second part analyzes relative scenes in this movie and the last part will list environment problems in this movie and come up with some solutions.Through the analysis and understanding of the environmental protection consciousness reflected by the movie,the author hopes to raise people's awareness to protect this fragile environment and then make some contributions to improve people's living environment for the survival of mankind.

Polymer Coatings for Protection of Wood and Wood-Based Materials

Three major types of protective coating of wood and wood-based materials have been considered. These three types include the coatings based on carboxyl-containing water-soluble polymers which are easily cross-linked by inorganic salts or OH-containing compounds, pH-sensitive coatings and polymer multi-layer structures. First of three mentioned approaches allows affecting permeability and enhancing the prevention the loss of water from the surface of wood to its surrounding. The advantage of the second approach is its ability to vary and purposely adjust the polymer composition and the number and distribution of -COOH groups in the chain which make the originally water-soluble polymers completely insoluble. The strong feature of the third approach which includes broad use of hydrogen-bonded films produced by layer-by-layer self-assembly is the possibility of manipulation of coatings stability after construction.

基于电沉积水热法的钢表面Mg-Al-NO_(3)-LDH膜原位生长制备及沉积电位优化

为提升建筑用钢的耐久性,通过电沉积法在钢表面形成层状双氢氧化物(LDH)晶核,再通过水热反应让LDH晶核生长成形成致密的Mg-Al-NO_(3)-LDH膜,分析了电沉积电位对钢基底表面LDH膜生长的影响,讨论了LDH膜的形成机理.结果表明,当电沉积电位为-1.4 V(相对于Ag/AgCl电极)时,LDH纳米片聚集堆叠致密,形成的LDH膜结构最为密实,实现了对钢基底良好的锈蚀防护.

Development of Film Forming Agent HN-1 and Its Application in Drilling Fluid

Borehole instability and reservoir damage had become the international technical problems of petroleum exploration and development of complicated area, and the water of drilling fluid invading borehole wall and petroleum reservoir was the main cause of borehole instability and reservoir damage. In order to prevent the water of drilling fluid invading borehole wall and petroleum reservoir, domestic and foreign scholars recently put forward the technology of ultra-low permeable drilling fluid. Film forming agent was the key treating agent of ultra-low permeable drilling fluid, the film forming agent (HN-1) was developed, which did not affect properties of the drilling fluid and could decrease the filter loss of drilling fluid applied in Enping 24-2 oil field. Based on this research, ultra-low permeable drilling fluid could be applied to Enping 24-2 oil field. By the methods of testing ultra-low permeable drilling fluid properties, the drilling fluid invasion sand-bed depth, drilling fluid high temperature/high pressure (HTHP) sand-bed filter loss, the pressure-bearing ability of rock core and the ability of reservoir protection were studied. By synergistic effect, HN-1 containing the organic silicate and natural fiber polymer modified by organic amine prevented the liquid and solids in drilling fluid invading reservoir, decreased drilling fluid invasion sand-bed depth and drilling fluid HTHP sand-bed filter loss, improved the pressure-bearing ability of rock core and the ability of reservoir protection. The drilling fluid could decrease reservoir damage to the maximal degree, and it offered efficiency guarantee for exploitation Enping 24-2 oil field.

VO_(2)薄膜材料的变温光学性质及1550 nm激光防护性能研究

具有半导体-金属态相变性质的二氧化钒材料可用于光电探测器的激光致盲防护。本文报道了基于磁控溅射法制备二氧化钒薄膜材料的结构、形貌特性,以及在不同温度下的光学性质。使用椭偏光谱法测量了20~100℃下可见-近红外波段二氧化钒材料的椭偏参数,利用Gaussian、Lorentz模型获取了薄膜在相变前的光学性质,结合Drude模型拟合获取了材料在相变后的光学特性,获取了材料在300~1700 nm之间的变温折射率和消光系数等参数。变功率下1550 nm红外激光透射率的实验测试研究表明,VO_(2)薄膜样品的相变阈值功率为12 W/cm^(2),相变前后透射率由51%减小到15%~17%,开关率为69%。

NiCr薄膜换能组件静电放电响应分析与防护

目的 针对NiCr薄膜换能组件易受到人体静电干扰的问题,提出一种分析其静电放电响应特性的方法,并设计一种基于瞬态电压抑制(TVS)二极管的静电防护方案,提高其抗静电干扰的能力。方法 基于理论分析和COMSOL多物理场仿真软件,构建NiCr薄膜换能组件的静电放电模型,研究其在人体静电环境下的响应特性,并设计TVS二极管作为防护措施。结果 通过研究NiCr薄膜换能组件的静电响应特性,得到了其桥区温度及温度分布。结果显示,采用TVS二极管的静电防护设计能显著降低静电干扰,并表现出优异的防护效果。结论 在人体静电放电环境下,NiCr薄膜换能组件的桥区长度对温度无显著影响,但桥区温度随宽度和厚度的增加而降低。仿真和实验结果的峰值电流误差在2.5%以内,且峰值电流降低了40%,验证了TVS二极管在静电防护中的有效性,有助于提升NiCr薄膜换能组件的可靠性与安全性。

汽车涂装前处理用硅烷膜技术研究进展

随着汽车行业的快速发展,对汽车钢板的腐蚀防护需求日益增加,基于表面处理的环保型硅烷腐蚀防护膜因其优异的性能而备受关注。本文系统综述了硅烷腐蚀防护膜的耐蚀机制、性能测试与评估方法,详细分析了影响其性能的关键因素,并提出了结构优化策略。同时,也讨论了当前领域中存在的技术挑战和未来发展趋势。通过综述,可以为提高汽车钢板的腐蚀防护能力、延长汽车寿命、降低维护成本以及实现可持续性发展提供重要的理论和实践指导,推动汽车制造业朝着更高效、环保和可持续的方向发展。

Quasi-in-situ Observation and SKPFM Studies on Phosphate Protective Film and Surface Micro-Galvanic Corrosion in Biological Mg-3Zn-xNd Alloys

The phosphate protective film and micro-galvanic corrosion of biological Mg-3Zn-xNd (x = 0, 0.6, 1.2) alloys were investigated by scanning and transmission electron microscopy, quasi-in-situ observation, scanning Kelvin probe force microscopy (SKPFM) and electrochemical tests. The results revealed the Mg-Zn-Nd phases formed in Mg-3Zn alloy contained with Nd. Adding Nd resulted in a significant decline in the cracks of the phosphate protective film and micro-galvanic corrosion of alloys, which were recorded by quasi-in-situ observation. In addition, the Volta potential difference of Mg-Zn-Nd/α-Mg (~ 188 mV) was lower than MgZn/α-Mg (~ 419 mV) and Zn-rich/α-Mg (~ 260 mV), and the corrosion rates of alloys markedly decreased after the addition of 0.6 wt% Nd. The improvement in corrosion resistance of Nd-containing alloys was mainly attributed to the following: (i) the addition of Nd reduced the Volta potential difference (second phases/α-Mg);(ii) the phosphate protective film containing Nd_(2)O_(3) deposited on the surface of the alloys, effectively preventing the penetration of harmful anions.