Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《中国腐蚀与防护学报》
Abstract： The evolution of corrosion product film formed on X80 pipeline steel in artificial solution， which simulate the soil medium at Ku'erle area, with different immersion time was studied by immersion tests, while the morphology and phase constituent of the corrosion product film was characterized by means of scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. The effect of corrosion product film on the pitting corrosion of X80 pipeline steel was investigated by cyclic polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that the thickness and compactness of corrosion product film gradually increased with increasing immersion time. After immersion for 168 h, the corrosion product film was clearly divided into two layers. The pitting of X80 pipeline steel may be hindered or inhibited by the corrosion product film, which may reduce the probability of pitting initiation, and increase the resistance to pitting growth.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： The Ni-Fe alloy coating with Ce was electroplated on the 20# steel by adjusting the concentration of CeCl3 in plating solution with the rare earth cerium salt CeCl3 as the additive. The relevant microstructure and corrosion behavior in 3.5%NaCl solution of coatings were studied by means of SEM, EDS and XRD, as well as electrochemical polarization curve and impedance spectroscopy. The results indicate that rare earth additive in acidic bath is extremely favor of the generation of sol Ce(OH)3, but restrains the generation of (FeOH) and Fe(OH)2 etc. With cathodic adsorptive characteristics the adsorption of Ce(OH)3 would compete with the adsorption of (FeOH). The former is preferentially absorpt on the surface of material, which restrains the generation of Fe. On the other hand, the addition of CeCl3 improves the current efficiency greatly, so as to increase the deposition rate. When concentration of CeCl3 is 3 g/L, the coating with better quality and better corrosion resistance would be obtained with the content of Fe controlled to about 16%.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： The effect of heat treatment temperature on the microstructural evolution of electroless plated Ni-P coatings was investigated using X-ray diffraction (XRD) analysis. The results showed that the as plated electroless Ni-P coating is amorphous. After heat treatment at 350 ℃, Ni-P coatings turn into crystalline state, while Ni3P phase appeared at 400 ℃. With the increasing heat treatment temperature, the Ca2 + atomic percentage of the formed fouling scales reduced firstly at 300 ℃, and then increased at 350 and 400 ℃. After heat treatment at 300 ℃, the internal stress and hydrogen embrittleness of the coating was eliminated, thereby, the anti- fouling performance and corrosion resistance of the coating was enhanced.
Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract：为了掌握时效处理后的2205双相不锈钢在氢氟酸溶液中的腐蚀行为，实验室通过金相显微镜观察了固溶处理后的2205双相不锈钢经800℃时效处理15分钟、60分钟和120分钟的显微组织，采用XRD分析了时效不同时间下的物相结构，借助电化学极化和电化学阻抗方法测试了时效时间对2205双相不锈钢抗氢氟酸腐蚀行为的影响规律。结果表明：当时效时间从15分钟延长到120分钟，双相钢内析出了σ相，且σ相含量随时间延长而增多，铁素体基体相的含量则逐渐减少。随着时效时间延长，2205双相不锈钢的自腐蚀电流密度和维钝电流密度都呈逐渐增大趋势，抗氢氟酸腐蚀性能下降，这主要是因为析出的σ相导致钝化膜内的载流子密度逐渐增大，加快了电子的传输速度，电化学反应更容易发生。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-14 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：采用动电位极化曲线分析了X100和X80管线钢在0.5 mol/L NaHCO3溶液中的极化行为，通过电流密度-时间曲线以及Mott-Schottky曲线考察了两种钝化膜的生长机制和钝化膜的半导体性质，借助电容测量和点缺陷模型(PDM)计算了两种钝化膜内的缺陷密度和缺陷扩散系数。结果表明：两种管线钢在该介质中都存在一个很宽的钝化区间，表面钝化膜的生长均受电迁移和溶解—沉积混合机制控制，钝化膜均为n型半导体。但与X80管线钢相比，X100钢具有更低的自腐蚀电流密度和维钝电流密度，更高的击穿电位。X100管线钢表面钝化膜也更为致密、均匀、稳定，钝化膜的施主密度更低，缺陷扩散系数约是X80管线钢的1/3。因此，X100比X80管线钢表现出更好的抗均匀腐蚀性能和抗点蚀性能。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-07 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：通过浸泡实验考察了不同腐蚀时间下X80管线钢在库尔勒土壤模拟溶液中形成的腐蚀产物膜的变化规律，并通过扫描电镜和X-射线衍射仪观察和分析了腐蚀产物膜的形貌和组成；通过循环极化曲线和交流阻抗等方法，研究了腐蚀产物膜对X80管线钢点腐蚀行为的影响规律，分析了影响原因。实验结果表明：随着浸泡时间的延长，X80管线钢表面形成的腐蚀产物膜逐渐增厚，致密性逐渐提高。当腐蚀7天以后，腐蚀产物膜明显地分为了内外两层。表面存在的腐蚀产物膜可以阻碍或抑制X80管线钢的点蚀行为，这主要是因为表面腐蚀产物膜减少了蚀孔萌生的几率，增大了蚀孔长大的阻力。
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