Assessing the corrosion protection property of coatings loaded with corrosion inhibitors using the real-time atmospheric corrosion monitoring technique

The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.

Copper corrosion in hot and dry atmosphere environment in Turpan, China

The atmospheric corrosion behavior of pure copper exposed for three years in Turpan, China, which is a typical hot and dry atmosphere environment, was investigated using mass-loss tests, morphology observations, composition analyses, and electrochemical techniques. The results indicated that the annual corrosion rate of pure copper was approximately 2.90 μm/a. An uneven distribution of corrosion products was observed by scanning electron microscopy; this uneven distribution was attributed to the dehydration process during wet–dry and cold–hot cycles, and the compositions mainly consisted of cuprite （Cu2O） and atacamite （Cu2Cl（OH）3）. Electrochemical measurements showed that deposits on copper improved its resistance to corrosion and the protectiveness decreased with increasing temperature. On the other hand, results obtained using the scanning vibrating electrode technique showed that the porous and uneven structure of the deposit layer generated a spatial separation of cathodic and anodic reaction sites, which accelerated the corrosion process in wet and rainy weather.

Amine-based solvent for CO_2 absorption and its impact on carbon steel corrosion: A perspective review

Carbon dioxide(CO2)is one of the commonly emitted gaseous by-products in industrial processes.While CO2 gas is the main cause to greenhouse effect,various CO2 capture technologies have been proposed and implemented to sequester the CO2 before the waste gases being released into the atmosphere.One of the mature technologies for CO2 absorption is by using amine-based solvents.In this regard,different single amine solvents or blended amine solvents have been proven for their capability to remove CO2.However,the dissolution and reaction of CO2 gas with the amine solvents turn the solution corrosive.Such phenomenon is undesired as it posts corrosion problem to the absorption column,which normally built of carbon steel material.Henceforth,understanding the behaviour of different amine-based solvents in absorbing CO2 and its subsequent impact on carbon steel corrosion is very significant.In this review article,we will outline some of the more commonly used solvents and their respective advantages and disadvantages,motivating further investigation into the corrosion tendency.Meanwhile,existing gaps in this research area are discussed for future investigation.

Superior corrosion resistance-dependent laser energy density in(CoCrFeNi)95Nb5 high entropy alloy coating fabricated by laser cladding

(CoCrFeNi)95Nb5 high entropy alloy(HEA)coatings were successfully fabricated on a substrate of Q235 steel by laser cladding technology.These(CoCrFeNi)95Nb5 HEA coatings possess excellent properties,particularly corrosion resistance,which is clearly superior to that of some typical bulk HEA and common engineering alloys.In order to obtain appropriate laser cladding preparation process parameters,the effects of laser energy density on the microstructure,microhardness,and corrosion resistance of(CoCrFeNi)95Nb5 HEA coating were closely studied.Results showed that as the laser energy density increases,precipitation of the Laves phase in(CoCrFeNi)95Nb5 HEA coating gradually decreases,and diffusion of the Fe element in the substrate intensifies,affecting the integrity of the(CoCrFeNi)95Nb5 HEA.This decreases the microhardness of(CoCrFeNi)95Nb5 HEA coatings.Moreover,the relative content of Cr2O3,Cr(OH)3,and Nb2O5 in the surface passive film of the coating decreases with increasing energy density,causing corrosion resistance to decrease.This study demonstrates the controllability of a high-performance HEA coating using laser cladding technology,which has significance for the laser cladding preparation of other CoCrFeNi-system HEA coatings.

Corrosion properties in a simulated body fluid of Mg/β-TCP composites prepared by powder metallurgy

Magnesium matrix composites （MMC） reinforced with 5wt% tricalcium phosphate （TCP） particles were prepared by powder metallurgy. Pure magnesium （CP-Mg） was fabricated by the same procedure for comparison. Scanning electron microscopy and en- ergy-dispersive X-ray spectroscopy analyses revealed that TCP particles were distributed homogeneously in the MMC. In order to investi- gate the corrosion properties, MMC samples were immersed in a simulated body fluid （SBF） at 310~0.5 K for 72 h. The mass loss of the samples in SBF and the pH values of the SBF were evaluated. Moreover, electrochemical measurements were conducted in the SBF. It was shown that the corrosion rate of the MMC decreased with the addition of TCP compared with CP-Mg. Hydroxyapatite was formed on the surface of MMC samples after immersion in the SBF for 72 h but not on the surface of CP-Mg.

STUDY ON CORROSION BETWEEN FLEXIBLE GRAPHITE AND METAL AND ITS PROCTECTION

In this paper, the mechanism of corrosion between flexible graphite which is used as a sealing material and metal is in-vestigated, the anticorrosive measures are introduced, and some mordern measures which should be paid attention are provided.

A Study of Multi-Permeating TiN/Ti Alloying Layer Using Plasma Surface Alloying Technology

TiN/Ti multi-permeating alloying layer has been formed on the low carbon steel by means of the double glow-discharge plasma surface alloying technique and hollow-cathode effect. The alloying layer was detected by axiovert 25 CA optical microscope with computer analyzing software （LEC）, GDA-2 glow discharge spectroscopy （GDS）, X-ray diffraction （XRD） and galvanochemical method. The results showed that the thickness of TiN/Ti multi-permeating alloying layer was about 10μm, the content of Ti on the surface was up to 63.48 wt% and the content of N was up to 12.46 wt%. The atom Ti and N concentrations changed gradually across the depth of the alloying layer and the preferred orientation of TiN/Ti alloying layer was crystal surface （200）. The multi-permeating alloying layer and substrate were combined through metallurgy. The surface appearances of the multi-permeating alloying layer were uniform and of a compact cellular structure. The hardness of the surface was about 1600-3000 HV0.1. The corrosion resistance of the permeating TiN/Ti alloying layer in 0.5 mol/L H2SO4 solution was greatly increased and the corrosion rate was only 0.3082 g/m^2. h.

Analysis of the quick corrosion of blast furnaces’gas pipes after the installation of dry-type de-dusting equipment and discussion about measures

Compared with the traditional wet-type de-dusting technology ,the dry-type de-dusting technology is considered to be environmentally friendly and energy-saving. However, the pipes carrying the de-dusted blast fiLrnace gas （BFG） tends to be corrosive more quickly and seriously. In order to investigate the reasons for the quick corrosion, the gas pipes and auxiliary bellows installed in Baosteel＇ s newly built BFG dry-type de-dusting system are studied. The corrosive properties of the condensed water, such as the pH value, are measured and analyzed. Meanwhile, various factors that may influence the corrosion rate of the pipes are studied by experiment. On the basis of the investigation and research, the causes of corrosion and leakage on the pipes are discovered. It is the process of dry de-dusting that is responsible ,to a large extent, for the quick corrosion of the pipes. The equipment of spray tower is introduced and its effects are then discussed. This tower is designed to eliminate most of chloridion and neutralized the acid by spraying the alkaline water to the dedusted gas flow. The practical operation shows that the tower helps to lessen the corrosiveness of the dry de-dusted gas effectively. The last part of this study analyzes the possible impacts of the dry-type de-dusting process of the newly built blast furnace （BF） on the main BFG piping which has been in the state of being corroded for years by estimating its potential corrosion rate, and some suggestions on maintenance are given as well.

Research of Electrochemical Noise Technology on Corrosion Resistance

This paper is focus on the corrosion resistance property analysis on three electric blasting of the coating-FeAl,FeCrAl,FeCrAlRE by electrochemical noise technology,acceleration of copper acetate salt spray accelerated corrosion test.According to a comparative analysis of three tests coated by the Impedance curve,FeCrAlRE coating power spectral density(SPD)curve and Power curve,FeAl,FeCrAlRE coating has two more notable for the corrosion resistance properties than FeAl,FeCrAl coatings.

海洋环境下铝合金腐蚀与防护的研究进展探析

铝合金因具有较好的耐蚀性能和加工性能,并且本身也具有质量轻、强度好等优点,在海洋船舶和海洋工程装备等领域得到了非常广泛的应用。随着对海洋资源的探索,船舶及海洋工程装备领域迎来了快速发展时期。由于海洋环境的特殊性和复杂性,在深海或者极端环境下铝合金也有广泛应用的可能性,在深海油气勘探和极地航行船舶等设备中,铝合金可以作为结构材料,因其质量轻、耐腐蚀性能好,得到了广泛应用,但存在着诸多腐蚀铝合金的因素,给船舶及海洋工程装备的发展造成严重的影响。基于国内外最新相关研究进展,针对铝合金的种类、腐蚀类型、腐蚀监测技术以及腐蚀防护技术进行了综合分析,探究铝合金在海洋环境中的腐蚀行为以及不同的防腐技术,为将来铝合金在深海或极端海洋工程领域的应用以及改善和提高铝合金防腐技术研究提供借鉴。

含汞油气田汞腐蚀与控制技术现状

介绍了含汞油气田在国内外的分布和汞含量的情况,以及汞在油气田中常见的存在形态与特性,阐述了金属及其合金的4种腐蚀破坏机理,系统调研了国内外汞及其化合物对油气田管道与设备的常见金属及其合金的腐蚀特征与控制技术研究与应用现状,提出今后需要加强含汞油气田腐蚀与污染及其防护的研究与应用的方向或问题。

低频导波检测技术在输油场站应用的效果分析

本文主要是对低频导波检测技术原理和应用进行分析,进而选取本次最优开挖验证点,通过MsS长距离超声导波检测仪在姬塬外输总站管网腐蚀检测过程中的应用效果分析,判断其应用效果具有哪些局限性和优缺点,为后续输油场站常规检测工作提供参考依据。

基于VMD-HT和深度学习的流噪环境腐蚀损伤声发射识别模型

对在役管道进行腐蚀声发射监测的过程中,管内介质流动产生的噪声同样会被传感器接收,导致腐蚀信号被覆盖从而引发误判。针对这一问题,提出了一种基于变分模态分解(VMD)、希尔伯特变换(HT)和深度双向门限循环单元神经网络(BiGRU)的流噪环境腐蚀损伤声发射识别模型。该模型能够将原始信号自适应地转化成多个本征模态分量,并提取各分量的瞬时频率及谱熵构建多维时序特征矩阵,进而建立原始信号与多维特征之间的映射关系。为验证该方法的有效性,对在役管道进行腐蚀声发射监测试验。结果表明,所提模型在流噪环境下具有良好的鲁棒性,监测数据的识别准确率达96.3%,可作为一种解决在役管道腐蚀声发射监测的新方案。

盐渍土区域基础混凝土防腐蚀施工技术措施研究

混凝土是重要的建筑材料,其应用于建筑工程时,应关注防腐蚀施工技术措施的运用,尤其是在盐渍土区域。以盐渍土区域基础混凝土防腐蚀施工的必要性为切入点,在此基础上,分析其施工技术措施,包括信息采集、方案分析、材料控制、现场施工、防腐检验与跟踪等。最后对盐渍土区域基础混凝土防腐蚀施工技术进行展望,服务后续工作,进一步提高混凝土结构的质量水平和防腐蚀能力。

套损井腐蚀机理分析及防治技术研究

油田套损井是由于套管腐蚀、机械损伤等原因导致的套管失效现象。通过深入分析油田套损井的腐蚀机理及其对油田生产的影响,探讨了相应的防治技术。研究发现,套管腐蚀主要包括均匀腐蚀、局部腐蚀和应力腐蚀,其形成机制复杂,受环境因素、材料因素和操作因素的多重影响。通过电化学检测和无损检测技术,可以有效评估腐蚀程度,制定针对性的防腐措施。同时,还介绍了材料选择、阴极保护技术和缓蚀剂应用等防治技术,并通过实际案例验证了其有效性。研究表明,科学合理的腐蚀防治技术能显著延长套管的使用寿命,确保油田的安全稳定生产。

油田注水泵涂膜措施应用分析

针对油田注水泵长时间运行后泵体内部过流组件表面出现坑点和裂纹,泵内叶轮腐蚀、气蚀严重,泵效下降、单耗上升等问题,现场应用注水泵涂膜技术。通过在离心泵叶轮等过流部位涂覆优质涂料,提高泵内流道的光滑度,减小泵的水力损失,维持注水泵安全高效的运行。对三种涂膜技术进行对比,最后选定贝尔佐纳双组份1341修补剂。涂膜后的注水泵平均泵效上升2.28个百分点,平均注水单耗降低0.22kWh/m^(3),措施后的注水泵均达到了有益效果,解决了注水泵长期运行所引起的泵效下降、单耗上升的问题,节能效果明显,现场涂膜的4台注水泵年可节约电量275.6×10^(4)kWh,年节约电费194.05万元,具有良好的节电效果,经济效益显著,具有推广价值。

基于集成算法的腐蚀管道失效压力预测研究

为了提高腐蚀管道剩余强度的预测精度、解决单一预测模型易受训练数据的质量影响而发生运行及预测输出不稳定的问题,引入两种集成模型方法。首先对于串行结构集成方法,以支持向量回归(SVR)融合正余弦策略改进的黑猩猩优化算法(IChOA)为基础建立AdaBoost-IChOA-SVR模型;其次对于双层并行结构方法,根据预测问题筛选出相关性低且学习效果良好的预测算法作为第一层基预测器,调节新数据集形成方式及相关参数设置,建立Stacking堆叠集成模型。以含腐蚀缺陷管道失效压力爆破数据为例,利用MATLAB分别进行仿真模拟,与基础SVR和PSO-ELM模型的预测结果及评价指标进行对比分析。研究结果表明:集成预测模型具有更好的预测输出性能,且串行结构的AdaBoost集成学习模型的构造流程较为简洁,运行速度及精度更高;该模型对腐蚀缺陷管道失效压力预测问题的拟合度可达0.996,相对误差均值可达3.69%,可为后续腐蚀管道相关预测模型建立和防护维修策略制定提供参考。

冷鲜肉防腐保鲜技术研究进展

冷鲜肉由于在价格以及营养等方面具有优点,而广受大众青睐。但其在屠宰、加工、销售等环节易受微生物的污染,颜色、气味等品质也易发生变化造成货架期短等问题,制约了冷鲜肉行业的进一步发展。而在人口众多的中国,肉类消费水平一直处于世界前列,肉类贮藏、维持肉类及其制品的品质始终是亟需解决的问题。因此,防腐保鲜技术在我国肉类食品中显得尤为重要,其在肉类食品行业的发展中,具有广泛的应用前景。本文综述了冷鲜肉腐败变质的主要原因,包括微生物的污染、脂质氧化和肌红蛋白的变色,且对化学保鲜技术如有机酸类、微生物代谢产物类等技术和物理保鲜技术如包装技术、辐照技术等技术及其防腐机理进行阐述;另外列举了其在肉类保鲜中的应用现状,分析了保鲜技术的优点及其在应用中存在的局限性,并对未来保鲜技术做出展望,以期为冷鲜肉的防腐以及保鲜技术的进一步深入研究提供一定的理论基础。

激光功率对316L不锈钢熔覆层组织及性能的影响

为了解决316L不锈钢激光熔覆层成形差、耐腐蚀性低的问题,采用显微组织观察、硬度实验、常温冲击及电化学测试等试验方法,对不同激光功率下熔覆单层及多层熔覆层的成形、组织及性能进行检测和分析。结果表明,随着激光功率的增大,熔覆层高度呈现先增加后减小的变化趋势,熔覆层内部析出相的含量以及稀释率则呈现上升趋势;激光功率过小易引起熔覆层开裂,过大则会引起熔覆层晶粒异常长大;随着激光功率的增加,熔覆层硬度呈增大趋势,当激光功率达到450 W时,熔覆层与基材结合界面处硬度值达到最大,为475 HV;而熔覆层的冲击性能和耐腐蚀性能则随着激光功率的增大呈现下降趋势,当激光功率为300 W时,其冲击韧性最大为92 J,且熔覆层具有最优的耐腐蚀性能,腐蚀电位E_(corr)最高为-0.3 V,且腐蚀电流密度I_(corr)最小为0.165 A/cm^(2);因此,当熔覆速率为3 mm/s、送粉速率为14 g/min、搭接率为50%时,采用300 W激光功率制备的熔覆层可得到优异的冲击和耐腐蚀性能。研究结果可为316L激光熔覆层工艺调控及性能改善提供参考。