共查询到14条相似文献,搜索用时 140 毫秒
1.
2.
3.
4.
LC4铝合金的土壤盐浓差宏电池腐蚀 总被引:1,自引:0,他引:1
利用湿砂土作为模拟土壤 ,通过失重法及电化学方法相结合 ,研究了盐浓差 (2 .0 %Cl- 及 0 .0 2 %Cl- )对LC4铝合金的宏电池腐蚀的影响规律。结果表明 :位于高盐土壤中的试样为宏电池阳极而加速腐蚀 ,宏电池作用强度达到 4.2倍。 相似文献
5.
概述了土壤中宏电池腐蚀的研究历程、现状以及存在的问题,并提出应用多种电化学测试技术对土壤宏电池腐蚀之间的相互作用规律进行研究的展望。 相似文献
6.
利用极化曲线、电化学阻抗、扫描电镜和表面能谱等方法,研究了硫酸盐还原菌对X70钢在土壤中宏电池腐蚀的影响.结果表明,接菌或灭菌粘土和砂土组成的宏电池,砂土中试样为宏电池的阴极,粘土中试样为阳极;随实验时间的增加,接菌及灭菌粘土中自然埋藏X70钢腐蚀速率逐渐减小,而砂土中宏电池阳极的腐蚀速率一直相当高;接菌土壤宏电池的电流和电动势比灭菌的大,接菌及灭菌粘土中阳极的腐蚀速率分别是自然腐蚀速率的4.93和2.45倍;在宏电池阴阳极面积比15∶1情况下,接菌及灭菌粘土中宏电池阳极的腐蚀速率分别为宏电池阴阳极面积比11时的5.01及2.33倍. 相似文献
7.
碳钢的土壤盐浓差宏电池腐蚀研究 总被引:1,自引:1,他引:0
以潮湿砂土作为模拟土壤,把失重法与电化学方法相结合,研究了盐浓差(2.0%Cl^-及0.2%Cl^-)宏电池对Q235钢腐蚀的影响规律。结果表明,位于较高盐浓度土壤中的试样为宏电池的阳极而加速腐蚀,宏电池作用强度达到2.2倍。 相似文献
8.
利用电化学阻抗测试技术等,研究了X70钢在滨海盐渍土与海水构成的宏电池中的腐蚀行为。结果表明,构成宏电池之后,海水侧X70钢一直作为宏电池的阳极处于被腐蚀状态,其腐蚀速率为自然腐蚀速率的25.3倍,腐蚀过程主要受阴极反应控制;由于腐蚀产物膜和氯离子的双重作用使宏电池腐蚀速率先有一定程度的降低,然后迅速升高,再有所降低并趋于稳定。试验还发现土壤-海水构成的宏电池的电动势并没有表现出像常规土壤宏电池电动势那样的先升高后降低的趋势,而是先有一定程度的降低,然后迅速升高后趋于稳定,该过程主要受极化电阻的影响。 相似文献
9.
关于土壤中宏电池腐蚀的研究 总被引:3,自引:0,他引:3
概述了土壤中宏电池腐蚀的研究历程、现状、以及存在的问题,提出应用多种电化学测试技术研究影响土壤宏电池腐蚀的因素及条件;并指出,随着应用于地下的金属材料种类越来越多,地下金属构件多为异金属连接件,当异金属连接件经过土壤性质差异比较明显区段时,两种金属构件分别位于不同的土壤中,这种情况下就会有异金属接触腐蚀与土壤宏电池腐蚀的综合作用,因此,应该加强这方面的研究。 相似文献
10.
11.
12.
The incipient anode (or halo) effect often occurs on repaired reinforced concrete structures. The diagnosis of this problem is widely reported to be macrocell activity. This diagnosis is based on very limited data. Indeed potential measurements on field structures repaired with proprietary materials have provided data that suggest that macrocell activity is not a cause of incipient anode formation. Alternative mechanisms that may cause incipient anode activity include repair/parent material interface effects, residual chloride contamination within the parent concrete, and/or vibration damage to the steel/parent concrete interface during repair area preparation. 相似文献
13.
Investigation of steel corrosion in cracked concrete: Evaluation of macrocell and microcell rates using Tafel polarization response 总被引:1,自引:0,他引:1
Inhomogeneous corrosion in reinforced concrete is investigated using a beam with a flexural crack intersecting the reinforcement. An Evans diagram representation of the macrocell corrosion system is developed. The relationship between the current density and the potentials relative to the crack obtained from the Tafel polarization responses of active and passive steel in concrete compares favorably with the experimental values. When both microcell and macrocell mechanisms contribute to metal loss at the crack, the Evans diagram representation indicates that an increase in the macrocell current density results in a decreasing contribution from the local microcell at the macrocell anode. 相似文献
14.
Reinforcement corrosion is still the most frequent reason for damage of concrete structures. It can be caused by carbonation or the ingress of chlorides. In cases of localized contaminations with chlorides, macrocells with very high corrosion rates can be established. Thereby the resulting macrocell current is dependent on many different boundary conditions like driving voltage, concrete resistivity and the geometrical arrangement of anode and cathode. In order to investigate macrocell corrosion, the herein presented research work was carried out by laboratory experiments and additionally by numerical analyses. First the numerical simulations were calibrated by laboratory measurements and thereafter, a numerical parameter study was carried out to increase the available database and identify the impact of changes in single parameters. As the focus is on geometrical effects, all laboratory specimens and numerical models were designed to represent practical conditions with diverse geometrical arrangements, e.g., slabs or beams with localized depassivations. In addition, parameters like concrete resistivity, driving voltage and cathode to anode surface area ratios have been varied. Thereafter, all results were used to derive cell factors for a simple macrocell current estimation. The present status of the project will be presented and discussed. 相似文献