转锈稳锈材料在石油钻采设备薄壁件表面的应用

石油钻采设备中存在部分薄壁板件(厚度不超过3 mm),在喷砂或喷丸过程中极易造成变形,故实际生产中只能手工打磨清理。但是手工打磨效率较低,且一旦手工清理不彻底,会影响产品的防腐质量。为提升石油钻采设备中薄壁防腐质量,引进了新材料——转锈稳锈材料。通过控制变量,使用拉拔仪检测不同变量下涂层附着力;对转锈稳锈材料和传统的手工处理进行比较,考察其对不同品牌的油漆是否具有兼容性。研究结果表明:转锈稳锈材料与传统的手工打磨清理相比在增加漆膜附着力方面更具有优势,而且与大多数的油漆具有兼容性。     

水性锈转化涂料的制备及性能

采用苯丙乳液与改性苯丙乳液共混作为成膜物质,以单宁酸为转锈剂,柠檬酸为配位剂,焦性没食子酸为转锈促进剂,再加入成膜助剂、有机胺类缓蚀剂、渗透剂等,制备了一种可应用于带锈钢材的水性锈转化涂料。通过正交试验和单因素试验确定了涂料的最优配方为:成膜物质65%,转锈剂5%,转锈促进剂2%,缓蚀剂0.6%,渗透剂2%,配位剂0.5%,成膜助剂1.6%,蒸馏水余量。采用塔菲尔极化曲线测量、中性盐雾试验和盐水浸泡试验考察了漆膜的耐蚀性。结果表明,所制水性锈转化涂膜可耐盐雾96 h,耐盐水浸泡168 h,且耐酸性较强,在pH为2的3.5%NaCl溶液中有保护作用。与两款市售涂料相比,该自制水性锈转化涂料具有更好的耐蚀性。     

Tuning the pH-responsiveness capability of poly(acrylic acid-co-itaconic acid)/NaOH hydrogel: Design,swelling, and rust removal evaluation

The swelling behavior of poly(acrylic acid-co-itaconic acid)/NaOH hydrogel as well as its ability for iron and copper rust removal was studied and established for the first time. Through an experimental design, the influence of the synthesis parameters on hydrogel response was determined. It was found that pH-responsiveness dependence of hydrogel determines its application. In alkaline media, the hydrogel acted as superabsorbent, while in acidic, the most outstanding property was its pickling capability that allowed to clean carbon steel and copper metallic surfaces. Infrared, thermogravimetry, and scanning electron microscopy were performed to determine copolymer formation, thermal properties, and morphology. Metallic crystallographic phases formed during the corrosion processes were determined by X-ray diffractometer. Hydrogel adhesiveness followed by diffusion and dissolution of metal oxides species was identified as the main steps in the rust removal mechanism. This method offers a new, environmentally friendly perspective to eliminate corrosion from metallic surfaces compared with traditional strategies. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48403.     

Inhibition of Spore Germination of Phakopsora Pachyrhizi Using Crude Extracts of Amaranthus Spinosus

The effectiveness of methanolic and n-hexane crude extracts of Amaranthus spinosus to inhibit the spore germination of Phakopsora pachyrhizi, a causal agent of soybean rust disease was studied. Both methanolic and n-hexane crude extracts inhibited spore germination at concentrations of 0.1% to 5.0%. Methanolic extract of the roots at a concentration of 2.5% inhibited 55% of spore germination, and this result was similar when higher concentration at 5% of methanolic and n-hexane extracts of the flowers was used. The presence of alkaloids, flavonoids, tannins, saponins, and terpenoids in the extract may be responsible for the inhibition. The extract was potential to be utilized as a botanical fungicide.     

5通道铁磁探测仪的研发与锅炉管堵塞检测

描述了5通道铁磁探测仪的研发和应用，该仪器能在管外发现发电锅炉过热器管和再热器管内是否有铁锈堆积，并评估堵塞程度，目的是通过检测防止爆管事故。采用磁学探测方法，在管外表面的1条圆周线上布置5个测量点，进行了有限元数值模拟和标定曲线的计算。对计算结果进行了实验验证，与计算值相比较，测量值的标准误差（相对误差）为5.2%。现场检测得到的堵塞面积与管内孔的面积之比，与X射线摄影测得的结果比较，确定铁磁探测仪检测的标准误差（绝对误差）为3.9%。通过为5家热电厂进行过热器管和再热器管堵塞检测，发现超标堵塞30多处，解剖验证无一误报，所以用该仪器进行堵塞检测能够防止上述锅炉管爆管事故。     

Characterization of superficial modification of ferrous rusted substrates subjected to dechlorination-electrochemical process

Preservation of archaeological artefacts after their removal from saline media is a difficult task due to the chloride content of the oxide layers which are unstable in atmospheric conditions, especially if the relative humidity exceeds 85%. For this reason, removal of chlorides from rust layers is one of the priorities of conservationists or restorers of historical artefacts. However, removal of chloride ions is not an easy procedure because of the many considerations involved in the process. In this research, artificially pre-rusted iron samples and an actual historical cannonball were subject to a dechlorination process in a potassium hydroxide solution to measure constant chloride release in a bulk solution. After the chloride removal process, a commercial protective layer was applied to the rust for stabilization purposes. It was calculated that the kinetics of the dechlorination process is driven by diffusion behaviour following Fick’s second law. When this diffusion process prevails, the dechlorination extraction affects the integrity of rust layers as is demonstrated with scanning electron microscopy and X-ray diffraction analyses. It was proven that the chloride removal procedure causes the studied iron layers to stiffen, provoking superficial modification and, in some cases, fractures of the rust. By means of electrochemical impedance spectroscopy it was calculated that the magnitude of the positive effect of the dechlorinated samples depends on the protective features of the rust. Therefore, this research reveals that an efficient chloride removal procedure depends on the electrochemical properties of the dechlorination process and the initial morphology of the iron rust.     

Investigation on the nickel content design and the corrosion resistance of low alloy steel welded joint in tropical marine atmosphere environment

In this study, three kinds of welding materials (WMs) with different Ni contents were designed for low alloy steel welded joints made by CO₂ gas-shielded welding technique. The corrosion resistance of welded joint was studied through the atmosphere exposure test in Trat, Thailand. Results show that there was a hardening in the heat-affected zone after welding, and the average hardness slightly increased with the increase of Ni in WM. The electrochemical activity at the fusion line zone enhanced with the addition of Ni in WM, indicating a more obvious local galvanic corrosion effect there. Ni promoted the generation of NiFe₂O₄ and the transformation from γ-FeOOH to α-FeOOH, which increased the impedance modulus of the rust film on WM. More important, the corrosion performance assessment illustrated that the addition of Ni in WM hardly had an effect on the corrosion step values after half a year test, which confirmed that there is no need to add excessive content of Ni.     

水基防锈剂的研究进展

金属因生锈每年造成巨大经济损失.目前的金属防锈技术存在很多缺点,相比之下,环保型水基防锈剂在金属材料保护方面有许多优点.综述了国内外近年来水基防锈剂的研究状况,重点介绍了几种新型水基防锈剂的防锈机理和性能,并简要概述了美国水基防锈剂的研究进展,最后提出了水基防锈剂的发展趋势,即利用丰富的自然资源或农副产品提取防锈剂的有效成分,经改性后制成高效低毒的复合水基防锈剂.     

Colour‐based assessment of atmospheric corrosion products,namely of flash rust,on steel

The paper reviews the utilization of colour analyses for the assessment and rating of atmospheric corrosion products, whereas particular attention is spent to flash rusting. The background of flash rust formation is discussed first, along with a brief review about the composition of flash rust. The fundamentals of the HSV colour model, which is selected as a simple suitable model, are introduced. Finally, the author discusses the utilization of the suggested approach for the evaluation of steel substrate cleanliness and rust assessment.