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The bipolar plate of AISI 1045 steel with chromized coatings prepared by low-temperature pack cementation for proton exchange membrane fuel cell 总被引:2,自引:0,他引:2
The low-temperature pack chromization, a reforming pack cementation process, is employed to modify AISI 1045 steel for the application of bipolar plates in PEMFC. The process is conducted to yield a coating, containing major Cr-carbides and minor Cr-nitrides, on the substrate in view of enhancing the steel's corrosion resistance and lowering interfacial contact resistance between the bipolar plate and gas diffusion layer. Electrical discharge machining and rolling approach are used as the pretreatment to produce an activated surface on the steel before pack chromization process to reduce operating temperatures and increase deposition rates. The rolled-chromized steel shows the lowest corrosion current density, 3 × 10−8 A cm−2, and the smallest interfacial contact resistance, 5.9 mΩ cm2, at 140 N cm−2 among all tested steels. This study clearly states the performance of 1045 carbon steel modified by activated and low-temperature pack chromization processes, which possess the potential to be bipolar plates in the application of PEMFC. 相似文献
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Magdalena Rzepka Fatih Özogul Krzysztof Surówka Magdalena Michalczyk 《International Journal of Food Science & Technology》2013,48(6):1318-1326
Quality and safety parameters of Atlantic bonito gravad during 42 days of storage at 7 ± 1 °C were analysed using monitoring sensory quality, microbial contamination, nucleotide degradation products, biogenic amines (BA), trimethylamine (TMA) and thiobarbituric acid reactive substances (TBARS). The shelf‐life of vacuum packed Atlantic bonito gravad was found to be 28 days. Total viable count (TVC) did not exceed 6 log CFU g?1. Malonodialdehyde (MDA) content did not surpass 10 mg kg?1. Nine biogenic amines were detected. Histamine level at the end of the storage was 355.3 mg kg?1. TMA increased from 53.9 to 619.1 mg kg?1. Among indicators based on the products of nucleotide degradation, the H value is best correlated with the sensory assessment. It can be concluded that the storage temperature of bonito gravad must be below 7 °C to prevent the threat to safety and quality posed by biogenic amines, especially histamine. 相似文献
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在考察了国内现有热轧带钢卷与型钢生产线的捆扎现状以及研究了国内外多种钢材打捆机的基础上,研制了一种全新的带钢卷、型钢全自动捆扎机。详细介绍了该捆扎机的整体结构;系统阐述了该捆扎机主要组成部分以及性能原理。该捆扎机结构巧妙,易于操作和维护,能适应各种恶劣的工作环境。 相似文献
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S. S. Satheesh Kumar S. Sathiyanarayanan A. Sambasiva Rao T. Raghu 《Transactions of the Indian Institute of Metals》2009,62(2):129-133
Low density, excellent corrosion resistance, moderate strengths at high temperatures make titanium based alloys candidate
materials for advanced aerospace structures. Advanced joining techniques are emulating for fabrication of complex aerospace
structures. Roll bonding is one such solid state joining technique where bonding between two rough and clean surfaces is obtained
under high temperature and pressure. The work horse dual phase titanium alloy Ti-6Al-4V finds extensive structural application
in aerospace and space industries. In the present study, two Ti-6Al-4V sheets are stacked together and encapsulated in a mild
steel can followed by evacuation and hot crimping. The pack is extensively deformed to ∼84% reduction in thickness employing
conventional hot rolling mill. Partially roll bonded 0.74mm thick sheets were obtained and microstructural evolution was studied
using light microscopy and scanning electron microscopy. The incompletely bonded interface was analyzed through elemental
mappings by Electron Probe Micro Analyzer and compared with completely bonded region. The partially bonded region revealed
the presence of aluminium oxide at the interface which possibly could have hindered complete bonding at that region. The room
temperature tensile properties of as- roll bonded Ti-6Al-4V nearly approaches the base material properties. 相似文献
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青海贵德ZR_1干热岩井钻进工艺研究 总被引:12,自引:2,他引:10
青海贵德ZR1干热岩井具有高温、高硬度、高研磨性的特点。在施工中优选聚磺钻井液体系,在高温高压下保持良好的流变性与较低的滤失量,满足干热岩井施工要求,应用效果好。通过分析地层岩性、岩石物性等因素,选择了适于该井高硬度、高研磨性地层钻进的牙轮钻头,并取得1.24 m/h平均机械钻速。通过实验与实践,掌握了高温井(130℃)固井工艺,固井止水质量检查合格。使用川5-4型取心器成功在高温、高压、较破碎地层完成了取心作业,取心率45%~83%。 相似文献