共查询到18条相似文献,搜索用时 78 毫秒
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通过分析TRT转子异常振动导致停机检修的原因,发现酸性液体的酸腐蚀,造成零部件的露点腐蚀;与此同时,煤气中的大量水分,对零部件形成冲蚀,故本次损伤是由于冲蚀和腐蚀综合作用引起的。腐蚀冲蚀共同作用下叶片出现开裂,或者涂层剥落,导致一方面因腐蚀作用转子质量分布不均匀;另一方面,由于开裂、涂层脱落,导致转子质量中心会漂移,高速运行过程中局部振动加剧。针对以上原因分析,消除质量中心漂移机制,打磨处理容易引起叶片弹性变化,保证TRT安全生产。 相似文献
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对某厂2号TRT透平机一级动叶片中断裂叶片的化学成分、宏观断口以及金相组织进行了分析,结果表明,该叶片属于腐蚀疲劳断裂,其疲劳裂纹起源于叶片进气边边缘部位的腐蚀麻点处,腐蚀麻点是由于叶片与湿积灰中的腐蚀性介质Cl-,SO4-等发生反应造成的。 相似文献
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蒸汽透平机叶片的使用环境恶劣。最后一级叶片承受着点蚀、应力腐蚀破裂(SCC)和腐蚀疲劳。使用蒸汽和燃气透平的电厂经常会发生叶片失效故障。有时;这些故障还会造成严重事故。对世界各国来说,研究叶片的安全和可靠性都是一个重要课题。现代发电行业的发展使最后一级叶片长度越来越长,产生故障的风险越来越大。 相似文献
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工作于低功率工况的燃气轮机动叶片和导向叶片材料在600℃~75℃产生一种低温热腐蚀。本文使用盐淋浴方法研究了In939,U500和543镍基高温合金于Na_2SO_4和NaCl混合盐中750℃热腐蚀性能。用电子探针和X射线衍射分析对腐蚀产物进行了分析。试验结果表明,In939合金在750℃时热腐蚀抗力低于另外两种合金。然而,三种合金产生热腐蚀的机制是一致的。由于腐蚀环境中有足够高的SO_3分压,促使试样表面的NiO硫化而生成Na_2SO_4和NiSO_4低熔共晶,因此加速硫化一氧化过程。 相似文献
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镍基高温合金是航空、航海及工业燃气轮机叶片的重要材料,在实际使用中常常发生比同温度下单纯氧化还要严重的热腐蚀现象。为了探明燃气轮机叶片的热腐蚀机理,长期以来,大多数研究者在实验室里进行模拟海洋环境下的热腐蚀试验。目前国内外普遍采用的热腐蚀实验方法为坩锅浸盐法和坩锅涂盐法。本文所涉及的镍基高温合金热腐蚀实验采用的是涂盐法,盐成分(质量分数)为75%Na2SO4 25%NaCl,反应温度800℃,反应时间为1 h。研究发现,即使NaCl以固态形式沉积在合金表面也会加速合金的腐蚀[1]。因此,镍基高温合金热腐蚀产物中的微量氯测定,对腐蚀机… 相似文献
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采用国际海事组织(IMO)模拟油轮货油舱内底板环境试验方法,对比分析了传统船板和耐腐蚀船板的腐蚀失重与腐蚀形貌,深入研究了环境温度对船用耐蚀钢腐蚀行为影响规律。结果表明,环境温度对船板腐蚀行为存在显著影响,随着环境温度(30~50℃)的升高,点蚀坑的数量逐渐增多,点蚀坑深度先增大后减小,在45℃时达到峰值。2种钢点蚀行?畋鸾洗螅炒甯值闶纯拥纳疃戎本侗龋╤/D)随环境温度的增大而增大,而耐蚀船板则呈现逐步下降的趋势。耐蚀合金元素的加入有效降低了船板钢在不同温度下的腐蚀速率,减小了钢的点蚀坑数量,改善了点蚀坑的扩展方式。即点蚀坑由纵向深度方向扩展,转为横向表面方向扩展,有效提高了船板的安全性。 相似文献
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Nicholas J. Carino 《Canadian Metallurgical Quarterly》1999,13(3):96-106
A critical step in selecting the most appropriate repair strategy for a distressed concrete structure is to determine the corrosion status of reinforcing bars. Because of the complexity of the corrosion process, it is prudent to involve personnel who are experienced in the corrosion of steel in concrete. The corrosion engineer may employ a variety of tools to help make an assessment of the corrosion conditions. This paper provides an overview of the corrosion of steel in concrete and presents some nondestructive electrochemical tools that are commonly used in corrosion investigations. The objective is to provide the repair specialist with basic information to allow effective communication with the corrosion engineer. Electrochemical principles involved in the corrosion of steel in concrete are reviewed. Subsequently, the half-cell potential method, the concrete resistivity test, and the linear polarization method are discussed. The principles of operation and the inherent limitations of these methods are emphasized. 相似文献
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C. M. Hansson 《Metallurgical and Materials Transactions A》2011,42(10):2952-2962
Almost all metals and alloys are unstable in the Earth’s atmosphere and will always be susceptible to corrosion. The basic
principles of corrosion are briefly described in order to explain the observations of corrosion, which render our personal
items as well as industrial machinery and public property dysfunctional, aesthetically displeasing, and potentially dangerous.
This is followed by a discussion, with case study examples, of three aspects of the impact of corrosion on society: (1) direct
effects resulting in injury or death, (2) contamination of the environment, and (3) the financial costs. 相似文献
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Corrosion Products and Formation Mechanism During Initial Stage of Atmospheric Corrosion of Carbon Steel 总被引:3,自引:0,他引:3
The formation and development of corrosion products on carbon steel surface during the initial stage of atmospheric corrosion in a laboratory simulated environment have been studied by scanning electron microscopy (SEM) and Raman spectroscopy. The results showed that two different shapes of corrosion products, that is, ring and chain, were formed in the initial stage of corrosion. MnS clusters were found in the nuclei of corrosion products at the active local corrosion sites. The ring-shaped products were composed of lepidocrocite (γ-FeOOH) and maghemite (γ-Fe2O2 ) transformed from lepidocrocite. The chain-type products were goethite (α-FeOOH). A formation mechanism of the corrosion products is proposed. 相似文献
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对钛生产过程中粗四氯化钛生产、粗四氯化钛精制、镁还原蒸馏制取海绵钛、海绵钛的后续处理、镁电解、镁精制几道工序中设备、管道存在的腐蚀情况进行了论述。针对存在的问题提出相应技术改进措施,从而提高了防腐蚀的工艺水平,延长设备使用年限,收到较好经济效果。 相似文献