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991.
分析了济钢10万m3低压湿式储气罐防腐失效的原因,从防腐涂料的选择、施工过程等环节提出了改进的措施,实施后效果良好。 相似文献
992.
Xiutong Wang Jizhou Duan Yan Li Jie Zhang Shide Ma Baorong Hou 《Bulletin of Materials Science》2005,28(2):81-85
Seabed sediment (SBS) is a special soil that is covered by seawater. With the developments in marine oil exploitation and
engineering, more and more steel structures have been buried in SBS. SBS corrosion has now become a serious problem in marine
environment and an important issue in corrosion science. In this paper, approach in the field of SBS corrosion is reviewed.
Electrochemical and microbial corrosion factors, corrosion mechanism, measurement of metal corrosion rate, corrosion evaluation
and prediction of corrosion are also discussed here. 相似文献
993.
The effects of anions like Cl-, Br-, NO
3
-
and SO
4
2-
on the anodic dissolution of the monolithic Al 6061 alloy have been investigated at neutral pH through immersion testing
and electrochemical techniques like potentiodynamic polarization and a.c. impedance spectroscopy. Scanning electron microscopy
was employed to characterize the corroded surface and to observe the extent of pitting in different media. From the evaluated
corrosion parameters it was found that the dissolution of the matrix was extensively reduced in presence of aqueous solutions
containing Br-, NO
3
-
and SO
4
2-
ions while Cl- ions aggravated corrosion by penetrating into the barrier oxide film on the surface of the material. Pronounced effect of
pitting was observed in presence of Cl- and the level of pitting in NO
3
-
and Br- were mild. In presence of SO
4
2-
ions passivity was extended over a wide potential range and breakdown of passivity occurs when the material was polarized
beyond pitting potential. The departure of capacitive behaviour towards resistive behaviour was clearly observed through impedance
measurements when investigations were conducted in Cl- media and in presence of the other electrolytes. Corrosion rates were, however, controlled during prolonged exposure in the
electrolytic media, specially in case of chloride media, due to the predominance of film repair kinetics. 相似文献
994.
It has become of paramount importance to be able to perform failure analysis of defects on hard disk surfaces quickly and accurately. In this study, ultrasonic pitting defects on hard disk surfaces were investigated. A new electrical tagging pattern system, which directly translated the channel bits to magnetic transitions during writing of the magnetic pattern around a defect, was used in the failure analysis of magnetic recording disks to mark defective sectors. With the help of the Kerr magneto-effect, the defective sectors were effectively located for further failure analysis. Results of the failure analysis revealed that there was 30% to 40% loss of the recorded magnetic bit signal due to an increase in the gap between a recording head and a hard disk surface with ultrasonic pitting defects. The experiments performed indicated that low ultrasonic power for disk cleaning could reduce the ultrasonic pitting defects significantly. The maximum failure rate due to single-type ultrasonic pitting defects was reduced from 33.4% to 16.7%, while the maximum failure rate due to cluster-type ultrasonic pitting defects was reduced from 11.1% to 5%. 相似文献
995.
阐述了低温水系统腐蚀结垢的原因及其危害。并提出了预防低温水系统腐蚀结垢的初步方案,可供低温水系统的运行管理提供参考。 相似文献
996.
The fatigue crack growth behaviors of Laser formed and ingot metallurgy (IM) Ti–6Al–4V alloys were studied in three environments: vacuum, air and 3.5% NaCl solution. Taking the Unified Fatigue Damage Approach, the fatigue crack growth data were analyzed with two intrinsic parameters, stress intensity amplitude ΔK and maximum stress intensity Kmax, and their limiting values ΔK* and . Fatigue crack growth rates da/dN were found increase with stress ratio R, highest in 3.5% NaCl solution, somewhat less in air and lowest in vacuum, and higher in IM alloy than in Laser formed one. In 3.5% NaCl solution, stress corrosion cracking (SCC) was superimposed on fatigue at R=0.9 for where Kmax>KISCC, the threshold stress intensity for SCC. This and environment-assisted fatigue crack growth were evidenced by the deviation in fatigue crack growth trajectory (ΔK* vs. curve) from the pure fatigue line where . Furthermore, the fractographic features, identified along the trajectory path, reflected the fatigue crack growth behaviors of both alloys in a given environment. 相似文献
997.
基体组织对合金结构钢耐海水腐蚀性能的影响 总被引:1,自引:0,他引:1
在实验室加速腐蚀试验和力学试验基础上,研究了合金结构钢基体组织中铁素体-珠光体比例与其在海水中的腐蚀速率和常规力学性能之间的关系。试验结果及分析表明:调整珠光体-贝氏体组织比例能够提高合金结构钢耐海水腐蚀性能和力学性能。 相似文献
998.
利用模糊综合评判评价注水管道腐蚀程度 总被引:4,自引:0,他引:4
注水管道腐蚀机理研究,需要进行注水管道的腐蚀程度评价。对腐蚀地面注水管道的腐蚀程度定量评价,能全面了解注水管道腐蚀情况基础,同时也是对注水管道剩余强度评价、剩余寿命预测以及可靠性分析的关键,为水质处理流程、缓蚀剂、杀菌剂和防垢剂等筛选提供了科学依据。提出了利用模糊综合评判方法对注水管道进行腐蚀程度评价的具体方法,通过应用示例验证了该评价方法的实用性。 相似文献
999.
1000.
发展了两种新型锆合金(N18,N36)作为PWR燃料元件包壳材料。研究了N18,N36两种锆合金的堆外性能。研究表明,具有均匀弥散分布的细小β-Nb或Zr(Fe,Cr)2第二相粒子的新合金表现出最好的抗腐蚀性能,N18和N36合金都有优良的耐腐蚀性能。合金的吸氢行为与其腐蚀行为成对应关系,而两种新型锆合金的吸氢比Zr-4合金的低。两种新锆合金的拉伸强度、爆破和蠕变性能也优于Zr-4合金。此外,两种新锆合金的热物理性能、织构和应力腐蚀行为相当或优于Zr-4合金。 相似文献