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通过场发射扫描电子显微镜,对不同腐蚀程度的65Mn珠光体片层进行大量观察实验。结果表明:其珠光体片层之间的铁素体和晶粒之间的先共析铁素体的腐蚀行为是以U型凹坑的方式被腐蚀,进而不断加深,直到整个晶粒的铁素体被腐蚀掉;在此期间渗碳体不会被腐蚀。研究结果与某些教材和专业书籍所述存在较大差异。 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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描述了超高压汽轮发电机组中压缸叶片的腐蚀特征,分析了叶片上产生积盐和沉积物下腐蚀的化学和电化学原因,提出了减缓腐蚀的有效措施. 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
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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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Mohamed I. Ismail 《国际钢铁研究》1979,50(10):453-456
The Direct Resistance Heating (DRH) of metals as a new technique for use in high temperature research on corrosion was tested. The behaviour of the pre-strained steel wires heated by this technique under different conditions and their properties and corrosion characteristics were studied. 相似文献
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镁合金的大气腐蚀试验研究 总被引:6,自引:0,他引:6
研究了镁锰合金在全国8个大气试验站暴露半年、一年的腐蚀行为,得到了镁锰合金在我国自然环境下的腐蚀速率。观察了腐蚀产物的形貌;讨论了腐蚀速率与环境因素的关系。结果表明:镁合金腐蚀行为和大气的污染程度和相对湿度有关,在大气污染严重和相对湿度大的地区,镁合金腐蚀比较严重。 相似文献
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V. V. Naumenko G. A. Filippov A. P. Shlyamnev I. P. Shabalov 《Steel in Translation》2012,41(12):1033-1039
Existing hypotheses regarding corrosion cracking are evaluated. None provides an exhaustive explanation of the phenomenon.
A generalized hydrogen-electrochemical hypothesis is free of the deficiencies of previous theories. 相似文献
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介绍了Incloy 825合金的化学成分及各元素的作用,给出了Incoloy 825合金的物理性能、机械性能、耐蚀性能,给出了Incoloy 825合金的组织,叙述了Incoloy 825合金的热处理、冷热加工、机加工、焊接工艺,列出了合金的适用技术条件、产品形状和用途。 相似文献
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Crack-propagation tests on a bulk metallic glass (BMG), Zr55Cu30Ni5Al10, were conducted either in aqueous sodium chloride (NaCl) solutions or in high-purity water under sinusoidal cyclic loading
or sustained loading. Although the crack growth rate in high-purity water was almost identical to that in air, the rate in
the NaCl solution was much higher than that in air, even in a very low concentration of NaCl such as 0.01 mass pct. In a 3.5 mass pct
NaCl solution, the time-based crack growth rate during cyclic loading, da/dt, was determined by the maximum stress-intensity factor, K
max, but was almost independent of the loading frequency and the stress ratio, and the rate was close to that of stress corrosion
cracking (SCC) under a sustained loading. 相似文献
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以耐海水腐蚀钢Q345C-NHY3+厚浆型环氧防锈漆涂装体系为研究对象,通过漆膜理化性能检测,结合中性盐雾、紫外光老化等实验研究了Q345C-NHY3的涂装特性与涂装腐蚀行为.同时采用EIS,考察研究了涂装体系在模拟海水介质中的中长期浸泡行为.结果表明:Q345C-NHY3+厚浆型环氧防锈漆涂装体系具有良好的耐阴极剥离性能,施加阴极保护可进一步提高体系的整体耐腐蚀性能.在模拟海水的介质中浸泡104 d后,涂层体系EIS谱的低频端表现出容抗特征,这表明溶液与钢板基体发生了电化学反应,涂层体系开始失效. 相似文献
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Recent studies have shown that the annual rates of consumer battery litter on urban pavements can be as high as 215 batteries per hectare of pavement and 0.4 batteries per meter of curb. As littered batteries deteriorate, they release components (Ag, Ba, Cd, Cr, Cu, Hg, Li, Mn, Na, Ni, Pb, Ti, and Zn) that can be significant sources of storm-water contamination. Results of ambient environmental and laboratory-accelerated corrosion studies are presented to quantify the mechanisms that yield chemical deterioration of littered batteries. The analysis concentrates on AA size alkaline and zinc chloride/zinc carbon (ZnCl/ZnC) cells since these are the most commonly littered batteries. Results indicate that littered batteries exposed to ambient well-drained environmental conditions for more than two months will develop surface corrosion over most of their surface but fewer than 10% will be ruptured by corrosion within the first 6 months. This agrees well with field observations. Exposure under poorly drained conditions yields more rapid deterioration but it requires exposure to more aggressive conditions such as those produced by road salts to reproduce the high degree of deterioration observed in some battery litter. 相似文献