Papers by Keyword: Sacrificial Anode

Abstract: Zinc plating using the principle of sacrificial anode is used to prevent steel corrosion. Pure zinc plating has some problems and Zn-Mn alloy plating has been studied as one of the measures to increase the corrosion resistance. Zn-Mn alloy plating can be applied to automotive parts requiring high corrosion resistance despite high plating cost. In this study, Zn-Mn alloy plating was electrodeposited in acidic chloride solution. The effects of electrolytic conditions on the composition of the alloy plating in the chloride bath were investigated. As the current density increased, the Zn content decreased and the Mn content increased. As the temperature of the electrolyte increased, the Zn content decreased and the Mn content increased.

Abstract: Aluminum alloy is well-known as a sacrificial anode material which can provide higher-electrochemical capacities than other types of sacrificial anodes. Al-Zn-In-Si alloys are primarily used to protect steel structures for marine application. The electrochemical behaviors of aluminum sacrificial anodes were investigated using experimental set-up conformed to NACE standard TM0190-2012. The electrochemical capacity of Al-5 wt% Zn-0.015 wt% In-0.1 wt% Si alloy is about 2,600 Ah/kg. The results indicate that the electrochemical capacities of Al-Zn-In-Si based alloys are improved by addition of Ti. Al-5 wt% Zn-0.015 wt% In-0.1 wt% Si alloy with Ti addition can provide higher-electrochemical capacities up to 2,747 Ah/kg.

Abstract: This study is to acquire the confirmation data regarding the cathodic protection characteristics for reinforced concrete beam specimens with zinc sacrificial anode in 15% salt water. It was possible to confirm the performance of sacrificial anode cathodic protection system by the measurement of potentials and concrete resistivity for the reinforced concrete beam specimens applied with zinc sacrificial anode in mortar topside of the concrete specimens. The corrosion potential and cathodic protection potential were measured by potentiostat, and 4 hour depolarization potentials were measured after disconnecting with anode for 4 hours. It was confirmed that the cathodic protection for reinforced concrete structures by means of zinc sacrificial anode were very effective corrosion protection technology in marine environments.

Abstract: In this work, the thermal spraying sacrificial anode was investigated as reinforced concrete structure cathodic protection method. During our experiment, the performance of the thermal spraying sacrificial anode was studied using electrochemical method, metallographic microscopy method and simulation tests. And the results show that the thermal spraying sacrificial anodes are better than traditional sacrificial anodes. The method of thermal spraying applied in sacrificial anode field is successful, which solve the problem of insufficient driving initial potential of traditional sacrificial anode in the concrete structure.

Abstract: In this paper, the sacrificial anode protection system for steel pile of Tripoli wharf (Lebanon) was studied. Optimal average protection current densities were selected for steel pipe/sheet pile of seaside zone back filled zone and sea mud zone. Based on field test and investigation, we found that the optimal average protection current density for seaside zone is 0.060 A/m², back filled zone 0.030 A/m² and sea mud zone 0.025 A/m², respectively.

Abstract: The effect of ca on the as-cast microstructure and electrochemical performance of AZ31 anode was investigated. The results show that addition of Ca to AZ31 anodes can result in not only grain refinement, but also a change in both morphology and volume fraction of the second phases. And grain refinement by Ca addition can be explained by the GRF mechanism. 0.4%Ca addition to as-cast AZ31 anode can increase the effective current capacity and current efficiency, and meet the requirements of magnesium sacrificial anode, but open circuit potential is lower than the nation standards. AZ31-0.4Ca anode will have a broad marketing application prospect.

Abstract: Electrochemical reduction of carbon dioxide (CO₂) to useful organic compounds is of great significance to decrease CO₂ emission. The electrochemical reduction of CO₂ is carried out in acetonitrile with tetrabutylammonium perchlorate as the electrolyte on a stainless steel cathode in a single cell; by using a sacrificial zinc anode, the product is zinc oxalate when the cathode potential is between 2.5 V and 3.5 V vs. Ag rod electrode. When the potential is less than 3.5 V, acetonitrile is decomposed, and the product is mainly zinc cyanide; when it is higher than 2.5 V, the main product is a basic zinc carbonate. Therefore, only when the cathode potential is in a proper range can CO₂ molecule obtain an electron and dimerize to form C₂O₄², which combines Zn²⁺ from the anode to form zinc oxalate.

Abstract: In the present study, corrosion and cathodic protection (CP) characteristics of concrete piles exposed to marine environments such as marine bridge columns or pier structures were evaluated under simulated conditions. The accelerated environmental tests were carried out at an elevated temperature (40°C) and a high chloride concentration (15%). The protection potential of CP systems with Zn-mesh sacrificial anodes applied to piles was inversely proportional to the water content in the concrete. When the CP system was applied after corrosion initiation and propagation (CProt), the protection current density was higher than when the CP system was applied at the beginning of structural construction (CPrev). However, the four-hour depolarization potential was higher in the latter case than in the former. In addition, it was found that even though the current density of the CPrev system was relatively lower than that of the CProt system, the CPrev system was also able to prevent corrosion. Consequently, both CProt and CPrev systems are very effective at preserving reinforced concrete structures, especially in marine environments.

Abstract: Sacrificial anode cathodic protection is one of the most widely used methods in protecting buried oil pipe lines against the corrosion damages. In the present work, a series of Aluminum alloys have been prepared as sacrificial anodes candidates to be used in the protection of the oil pipelines that pass through the Al-Hilla region. These prepared alloys were microstructurally and electrochemically characterized to evaluate their performance as Al-sacrificial anodes for cathodic protection of oil pipes The relationships between the protection potential with time, sacrificial anode life, discharge currents, and capacity of sacrificial anodes were found, taking into consideration the distance between sacrificial anode and protected steel sample. According to the results obtained, the best selection of sacrificial anodes was (Al-4% Zn-0.5% Sn) alloy at 30cm in Al-Hilla region.

Abstract: Sacrificial anodes performance of three iron alloys was measured by constant current test, The protection effects of iron alloys, zinc alloy and aluminum alloy sacrificial anodes on copper tube were compared and analysed by polarization test. The results show that all three iron alloys appearing well sacrificial anodes performance, with steady working potential, high practical electric capacity and current efficiency, the corrosion is uniform and the corrosion products fall easily. Iron alloys are more suitable for application on the cathodic protection of copper tube due to their more suitable driving voltage and coulpling current compared with zinc alloy and aluminum alloy.