耐H2S、CO2腐蚀新型涂料的研制与应用

H2S、CO2酸性腐蚀是目前我国化学工业、石油石化工业以及其他部门面临的一个普遍存在的问题，除了常规的酸性腐蚀之外还存在严重的氢致应力开裂（HIC）和硫化氢致应力开裂（SSCC）。采用环氧树脂和多异氰酸酯为涂料的成膜基料，加上高效抑制氢渗透、高效防止HIC和SSCC的填料所研制的涂料可以较好地解决这一问题。     

基于创新视角的油气储运问题对策研究

很多输油管道在湿硫化氢环境下受到严重腐蚀并开裂,如应力腐蚀开裂(SCC)、硫化物应力腐蚀开裂(SSCC)、氢致开裂(HIC)、应力诱导的氢致开裂(SOHIC)等。本文基于基于创新视角的油气储运问题对策进行了研究。     

X80级管线钢的发展及腐蚀实验研究概况

分析了我国的石油天然气消费利用及油气管道建设现状,对国内外X80管线钢的研制和应用情况进行了介绍,同时介绍了国内X80管线钢的腐蚀研究情况.介绍了不同pH值对X80管线钢土壤腐蚀行为的影响以及腐蚀产物钝化膜对钢表面的腐蚀行为与过程的影响.X80级管线钢的抗硫化物应力腐蚀开裂(SSCC)和氢致开裂(HIC)行为的结果表明...     

冷高压分离器在H2S环境下应力腐蚀开裂敏感性评估

针对制造过程中由于开孔失误而进行补焊的冷高压分离器在高压、高浓度的H₂S环境的使用安全问题,采用了电化学充氢、恒应变和慢拉伸的实验方法,研究了制造冷高压分离器的主体材料16Mn(HIC)钢和普通的16Mn钢及其焊缝的氢扩散系数,在不同H₂S浓度、pH值,模拟冷高压分离器操作环境溶液和实际溶液中的腐蚀规律和硫化氢应力腐蚀开裂（SSCC）敏感性,结合实际腐蚀环境的检测和分析结果,对补焊后的冷高压分离器的使用安全给出了综合评估.     

浅谈降低H_2S腐蚀的措施

当石油天然气环境中存在H2S气体时,硫化物应力腐蚀开裂(SSCC)是导致材料性能下降和失效的主要原因。极少量H2S的存在就足以导致一些敏感材料的应力腐蚀开裂(SSCC),本文简要介绍了金属材料在H2S环境中产生腐蚀磨损行为的机理,介绍了几种降低金属材料在H2S环境中应力腐蚀开裂的措施。     

再生塔换热器小浮头螺栓断裂分析

采用宏观和微观断口分析、金相显微组织分析、扫描电镜(SEM)以及能谱成分分析(EDS)等方法对扬子石化芳烃厂的换热器小浮头联结螺栓断裂的原因进行了研究,发现硫化氢应力腐蚀开裂(SSCC)和氢致开裂(H IC)是导致螺栓断裂的主要原因,并提出了有效的防护措施。     

加氢装置用阀门选材设计的探讨

针对加氢装置典型的腐蚀环境,对低温硫化氢腐蚀、高温氢和高温氢+硫化氢、硫氢化氨腐蚀和氯化铵腐蚀腐蚀行为进行讨论。针对4种不同的腐蚀环境下阀体选材进行了详细的分析,同时介绍阀体质量选择的要求。当处于硫化物应力腐蚀开裂(SSCC)环境时,可以使用镇静碳钢材料。在湿硫化氢腐蚀环境可以使用抗HIC碳钢,腐蚀特别严重时可以选择奥氏体不锈钢304L或者316L。氯化铵腐蚀和硫氢化氨腐蚀环境需要使用双相钢级别以上材料,甚至使用825合金。控制阀体材料本体质量也是提高阀门耐蚀性的重要措施。     

湿H2S环境下某气田高压压缩机橇选材设计

对于气田平台上的压缩机橇来说，CO₂和湿H₂S腐蚀会造成管道损坏，尤其湿H₂S的存在会引发氢致开裂(HIC)和硫化物应力腐蚀开裂(SCC)更会在短时间内造成难以弥补的损坏，且由于每级压缩伴随着温度、压力等的变化，使得防腐与选材成为压缩机管线一个比较重要的课题。从腐蚀计算出发，参考标准，综合考虑成本、力学及变化的环境等因素，通过ECE模型计算得到碳钢的腐蚀速率。从设计寿命出发，综合腐蚀裕量和经济及力学因素，从选材原则到选材方案解决某气田压缩机橇管道设计选材问题，旨为海油平台管道防腐与选材提供一定的借鉴与指导。     

波形膨胀节开裂的失效分析

分析了304不锈钢波形膨胀节开裂的原因,并采取有效措施预防恶性事故的发生。通过理化分析发现,304奥氏体不锈钢在冷加工成形时会发生马氏体相变;在开、停车情况下或保温不良时会形成湿硫化氢环境,因此含形变马氏体的304奥氏体不锈钢会发生湿硫化氢引起的氢致开裂(HIC)或应力导向氢致开裂(SOCHIC),当裂纹扩展到某一临界尺寸时便会发生低应力脆断。     

液化气球罐Zare合金防护层涂装工艺

液化气球罐在使用过程中因球罐内壁存在SSCC(硫化物应力腐蚀开裂)腐蚀环境,造成球罐内壁焊道热影响区出现裂纹,导致球罐内壁腐蚀.本文介绍了采用涂覆稀土合金(Zare)涂层和封闭剂的方法解决液化气球罐内壁SSCC腐蚀问题,着重讨论了球罐内壁防腐涂装工艺及其注意事项.     

Mathematical model for iron corrosion that eliminates chemical potential parameters

Iron corrosion in acidic media is a natural phenomenon that converts elemental iron to a more chemically-stable form, i.e. its oxide and hydroxide. In this study, the iron corrosion process is modeled as a completely implicit problem, solved by a novel finite difference model to provide insight into the ionic aspects of corrosion behavior. This new mathematical model eliminates the chemical potential parameters from the corrosion process equations, thereby reducing the need for experimental determination of chemical potentials. The eliminatedchemical-potential-parameters model predicts and quantifies key parameters (concentrations of conjugate base ion, iron (II) ion, hydrogen ion, anodic and cathodic potentials, and the electrical current density) associated with the iron corrosion process in acidic solutions. The rigorous derivation and novel application of the eliminated-chemical-potential-parameters model and its results provide new insights into the iron corrosion process. The present model is also applicable in any industrial process which is associated with metal corrosion. The model helps to guide the design of future corrosion resistant systems, and various experimental studies pertaining to corrosion inhibition techniques.     

Corrosion Inhibition of Mild Steel in Acidic Medium using 2-amino Thiophenoland 2-Cyanomethyl Benzothiazole

The corrosion inhibition characteristics of 2-amino thiophenol (ATP) and 2-cyanomethyl benzothiazole (CNMBT) on two types of steel in 1m HCl medium were investigated at different temperatures (25, 30, 35, 40 and 50°C). The pitting corrosion behaviour for the same system was studied using a potentiodynamic technique. The pitting corrosion resistance of steel samples increased with increase in concentration of the ATP and CNMBT. Some samples were examined by scanning electron microscopy. The effects of the inhibitors on the general corrosion of the two samples were investigated by using gravimetric and galvanostatic polarization techniques. The inhibition efficiencies increased with increase their concentration but decreased with increase in temperature. Free energies of activation, enthalpies and entropies for the inhibition processes were determined from rate constant data measured and different temperatures at different concentrations of ATP and CNMBT. Results were compared with fits obtained from the application of the Langmuir isotherm. Results were correlated to the chemical structure of the inhibitors. The inhibition efficiency of CNMBT is higher than that of ATP.     

Effect of H2S on the CO2 corrosion of carbon steel in acidic solutions

The objective of this study is to evaluate the effect of low-level hydrogen sulfide (H₂S) on carbon dioxide (CO₂) corrosion of carbon steel in acidic solutions, and to investigate the mechanism of iron sulfide scale formation in CO₂/H₂S environments. Corrosion tests were conducted using 1018 carbon steel in 1 wt.% NaCl solution (25 °C) at pH of 3 and 4, and under atmospheric pressure. The test solution was saturated with flowing gases that change with increasing time from CO₂ (stage 1) to CO₂/100 ppm H₂S (stage 2) and back to CO₂ (stage 3). Corrosion rate and behavior were investigated using linear polarization resistance (LPR) technique. Electrochemical impedance spectroscopy (EIS) and potentiodynamic tests were performed at the end of each stage. The morphology and compositions of surface corrosion products were analyzed using scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The results showed that the addition of 100 ppm H₂S to CO₂ induced rapid reduction in the corrosion rate at both pHs 3 and 4. This H₂S inhibition effect is attributed to the formation of thin FeS film (tarnish) on the steel surface that suppressed the anodic dissolution reaction. The study results suggested that the precipitation of iron sulfide as well as iron carbonate film is possible in the acidic solutions due to the local supersaturation in regions immediately above the steel surface, and these films provide corrosion protection in the acidic solutions.     

二氧化钛薄膜的制备及性能研究

二氧化钛具有无毒、光催化性能强,热稳定和化学结构稳定,耐腐蚀性能良好等特点,可作为半导体催化材料和耐腐蚀材料。二氧化钛薄膜可以采用物理的方法和化学的方法制备,薄膜态材料在未来将有着潜在的应用。本文结合近年来二氧化钛薄膜的研究进展,介绍了二氧化钛薄膜的制备方法和应用领域,并对未来二氧化钛薄膜的研究进行了展望。     

SnO_2-MnO_2-Sb_2O_3体系固溶体相图初探

采用化学共沉淀方法制备了SnO2-MnO2-Sb2O3三元固溶体并对其相图进行了初步研究,绘制了固相线下SnO2-MnO2-Sb2O3三元体系相图,确定该类固溶体的类型及其形成机制。实验结果表明:该三元体系的相关系图中含有2个单相区、8个两相区和3个三相区。金红石型SnO2为主要化合物的1区和锡锑共存互溶形成的(Sn,Sb)O2ss化合物为主的2区这两个单相区中的氧化物可以作为耐腐蚀性强、导电性良好的阳极材料中间层。     

La-Al2O3催化正丁醛自缩合合成辛烯醛反应

辛醇(2-乙基己醇)是一种重要的增塑剂醇。正丁醛自缩合合成辛烯醛是工业生产辛醇的重要步骤之一。为克服工业正丁醛自缩合反应因使用强碱水溶液催化剂所带来的设备腐蚀、污染环境、生产成本高等缺点,采用La改性γ-Al₂O₃催化剂(La-Al₂O₃)催化正丁醛自缩合反应。首先研究了制备方法和制备条件对La-Al₂O₃催化性能的影响,发现采用胶溶法、于700℃下焙烧4 h得到的La-Al₂O₃催化性能较好,具有相互匹配的酸碱中心是催化性能较好的关键。以适宜条件下制备的La-Al₂O₃为催化剂,研究了反应条件对正丁醛自缩合反应的影响,得到适宜的反应条件为:催化剂与正丁醛质量比为0.15、反应温度180℃、反应时间8 h。在此条件下,正丁醛的转化率最高达到90.6%,辛烯醛的选择性为91.7%。该催化剂重复使用4次,催化活性无明显下降。通过对反应液进行GC-MS分析,确定了正丁醛自缩合反应体系中的副产物,进而推测了可能的副反应,建立了La-Al₂O₃催化正丁醛自缩合合成辛烯醛的反应网络。     

WSA制酸系统生产运行中出现的问题及解决措施

分析了重庆钢铁股份公司焦化厂WSA制酸系统生产运行中出现的主要问题:SO2转化器腐蚀穿漏、焚烧炉系统火焰检测器熄火信号频繁出现、酸气切入前过程气温度达不到要求和酸气管道频繁堵塞等;提出了解决的方法:严格控制进入SO2转化器的蒸汽温度、改变火焰检测信号联锁输出时间、采用双酸气管道、按保温规范保温等,以供国内焦化行业的WSA制酸系统稳定运行参考。     

MDEA脱碳装置腐蚀原因探讨

概述国内外 MDEA脱碳装置腐蚀机理 ,对永安智胜化工联合公司合成氨厂脱碳装置腐蚀原因作分析并提出防腐技术措施。     

Some Schiff Base Surfactants as Steel-Corrosion Inhibitors

Two series of Schiff base amphiphiles were prepared by condensation of benzaldehyde or anisaldehyde with three different alkyl chain length fatty amines namely: dodecyl, hexadecyl and octadecyl amine. The chemical structures of the prepared Schiff bases were confirmed by using different techniques, (elemental analysis, FTIR and ¹H-NMR spectra). The data of structural analysis for these compounds were confirmed by the purity of the synthesized amphiphiles. The synthesized Schiff bases were evaluated as corrosion inhibitors for low carbon steel (mild steel) in various acidic media (HCl and H₂SO₄) using a weight loss technique. The corrosion inhibition measurements of these inhibitors showed high protection against corrosion process in the tested acidic media at different doses (50, 100, 150 and 200 ppm) as well as their having a good biocidal effect against sulphate reducing bacteria. The discussion correlated the efficient corrosion inhibition of these inhibitors to their chemical structures.     

Impact of SO2 concentration on the corrosion rate of X70 steel and iron in water-saturated supercritical CO2 mixed with SO2

The corrosion behavior of X70 steel and iron in water-saturated supercritical CO₂ mixed with SO₂ was investigated using weight-loss measurements. As a comparison, the instantaneous corrosion rate in the early stages for iron in the same corrosion environment was measured by resistance relaxation method. Surface analyzes using SEM/EDS, XRD and XPS were applied to study the morphology and chemical composition of the corroded sample surface. Weight-loss method results showed that the corrosion rate of X70 steel samples increased with SO₂ concentration, while the corrosion rate increased before decreasing with SO₂ concentration for iron sample. Comparing resistance relaxation method results with weight-loss method results, it is found that the instantaneous corrosion rate of iron is much higher than the uniform corrosion rate of the iron tablet specimens which are covered with thick corrosion product films after a long period of corrosion. The corrosion product films were mainly composed of FeSO₄ and FeSO₃ hydrates. The possible reaction mechanism under such environment was also analyzed, and the electrochemical reaction between the dissolved SO₂ in the condensed water film with iron is the critical reaction step.