scholarly journals The Effect of Increasing the Amount of Indium Alloying Material on the Efficiency of Sacrificial Aluminium Anodes

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1755
Author(s):  
Krzysztof Zakowski ◽  
Juliusz Orlikowski ◽  
Kazimierz Darowicki ◽  
Marcin Czekajlo ◽  
Piotr Iglinski ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Surface Profile ◽  
Zinc Content ◽  
Indium Content ◽  
General Corrosion ◽  
Alloy Matrix ◽  
Sacrificial Anodes ◽  
Aluminium Anodes ◽  
Lower Capacity ◽  
A Current

Al-Zn-In alloys having 4.2% zinc content and various indium content in the range of 0.02–0.2% were tested with respect to the most important electrochemical properties of sacrificial anodes in a cathodic protection, i.e., the current capacity and potential of the operating anode. The distribution of In and Zn in the tested alloys was mapped by means of the EDX technique, which demonstrated that these elements dissolve well in the alloy matrix and are evenly distributed within it. The current capacity of such alloys was determined by means of the method of determining the mass loss during the dissolution by a current of known charge. The results obtained demonstrate that the current capacity of Al-Zn-In alloy decreases with the increase in the In content, which results in an increased consumption of anode material and shorter lifetime of anodes. With 0.02% In content, the capacity amounted to approx. 2500 Ah/kg, whereas the alloy with 0.2% In had as much as 30% lower capacity amounting to approx. 1750 Ah/kg. Microscopic examination for the morphology and surface profile of the samples after their exposure demonstrated that a higher indium content in the alloy results in a more uneven general corrosion pattern during the dissolution of such alloy, and the cavities (pits) appearing on the alloy surface are larger and deeper. As the indium content is increased from 0.02% to 0.05%, the Al-Zn-In alloy potential decreases by about 50 mV to −1100 mV vs. Ag/AgCl electrode, which is advantageous in terms of using this alloy as a sacrificial anode. When the indium content is further increased from 0.05% to 0.2%, the potential of the alloy is no longer changed to a more negative one. The results obtained from all these tests demonstrate that alloys containing up to 0.05% of In additive are practically applicable for cathodic protection.

Navy Experimental Work with Cathodic Protection★

CORROSION ◽  
1956 ◽  
Vol 12 (3) ◽  
pp. 18-24 ◽  
Author(s):  
IRVING D. GESSOW
Keyword(s):  
Cathodic Protection ◽  
Corrosion Damage ◽  
High Resistivity ◽  
Sacrificial Anodes ◽  
Initial Cost ◽  
Protection Systems ◽  
Impressed Current ◽  
The Cost ◽  
Work Done ◽  
Polluted Waters

Abstract An account is given of work done by the Navy Bureau of Ships with cathodic protection of active and reserve ships. Because it is difficult to dissociate costs for maintenance and corrosion protection it is impossible to say whether or not the cost of cathodic protection of active ships is merited. Because corrosion damage to hulls seldom is considered except when perforations occur, or in destroyers and sub-marines where plates are thinner and original dimensions more critical, there is some belief that cathodic protection for all ships cannot be justified on a cost basis. With inactive ships, however, the reverse is true. Indefinite extension of drydocking times, the interval contingent on the exhaustion of anti-fouling paints, is anticipated. Initial cost of cathodic protection of active destroyers, submarines, and five types of reserve ships is tabulated. Details of cathodic protection systems for reserve ships are given. Criteria of protection differ somewhat from the accepted standards. In polluted waters inactive ships may require a potential in excess of 1 volt, while in other high resistivity waters 0.85 to 0.95 volts are sufficient. Some data are given on the cathodic protection of active ships. Merits of sacrificial anodes versus impressed current are listed. Extensive further activity in cathodically protecting active ships is contingent on the outcome of trials now under way.

scholarly journals Technology of composite erosion-radiation coating

2017 ◽  
Vol 2 (9) ◽  
pp. 9-16
Author(s):  
Владислав Смоленцев ◽  
Vladislav Smolentsev ◽  
Михаил Кондратьев ◽  
Mihail Kondratiev ◽  
Евгений Смоленцев ◽  
...  
Keyword(s):  
Surface Profile ◽  
Thick Layer ◽  
Plasma Beam ◽  
Simultaneous Impact ◽  
Profile Matching ◽  
Coating Formation ◽  
Process Behavior ◽  
The Impact ◽  
Manufacturing Science ◽  
A Current

A new method of composite treatment with the simultaneous impact of thermal energy of a current pulse and heat supply of a plasma beam is developed. The mechanism of a qualitative coating formation is shown at which the thick layer shaping with the improved micro-profile is achieved, where a micro-surface profile matching is achieved at the expense of the impact of concentrated energy supplied by a plasma beam to the surface of a molten coating causing an increased metal castability, its runoff from lugs into hollows and micro-irregularity height decrease. A mechanism of combined process behavior is developed which allowed creating a procedure of the design of technological modes, defining their place in technological transitions and substantiating maximum accessible technological potentialities of the method offered at the realization of working matters for science intensive products. The examples of the efficient use of a combined erosion-beam plasma treatment are shown, which extends a field of the method application and lightens a technological pre-production at the introduction into manufacturing science intensive products of new engineering generations.

Effect of quaternary addition on structure, electrical, mechanical and thermal properties of bismuth-tin-zinc rapidly solidified fusible alloy

2015 ◽  
Vol 7 (3) ◽  
pp. 1952-1958 ◽  
Author(s):  
Abu Bakr El-Bediwi
Keyword(s):  
Crystal Structure ◽  
Thermal Properties ◽  
Melting Point ◽  
Indium Content ◽  
Zinc Alloy ◽  
Mechanical And Thermal Properties ◽  
Alloy Matrix ◽  
Matrix Microstructure ◽  
Rapidly Solidified

Effect of quaternary addition, silver or indium, on structure, electrical, mechanical and thermal properties of bismuth-tin-zinc rapidly solidified fusible alloy have been investigated.  Adding silver or indium caused change in alloy matrix microstructure such as matrix parameters and crystal structure of formed phase.  A significant increase in bismuth-tin-zinc alloy strengthens with a little decreased in melting point after adding silver content.  But a significant decrease in bismuth-tin-zinc alloy melting point with a very little increase in alloy strengthens after adding indium content

The Corrosion Behaviour of Mg Alloy AZ91D/TiCp Metal Matrix Composite

2005 ◽  
Vol 488-489 ◽  
pp. 705-708 ◽  
Author(s):  
Suqiu Jia ◽  
Shu Sheng Jia ◽  
Guangping Sun ◽  
Jun Yao
Keyword(s):  
Metal Matrix ◽  
Corrosion Behaviour ◽  
Galvanic Corrosion ◽  
General Corrosion ◽  
Az91d Alloy ◽  
Alloy Matrix ◽  
Electrochemical Tests ◽  
Alloy Az91d ◽  
The Matrix ◽  
Carbide Particles

The corrosion of a magnesium-based MMC, comprising a AZ91D alloy matrix and 5 vol% titanium carbide particles has been studied in saline environments, using immersion and electrochemical tests. Corrosion was localized initially and developed subsequently into general corrosion , the local corrosion rate of AZ91D/TiCp being faster than diecast AZ91D due to the formation of less protective corrosion products. Galvanic corrosion for AZ91D/TiCp, due to coupling of the matrix and reinforcement, was more severe than diecast AZ91D.

Characterization of Al-Zn-Sn as Sacrificial Anodes to Protect Underground Oil Pipelines in Al-Hilla Regional

2012 ◽  
Vol 628 ◽  
pp. 135-143
Author(s):  
Kadhim F. Al-Sultani ◽  
Jenan Nasser Nabat
Keyword(s):  
Aluminum Alloys ◽  
Cathodic Protection ◽  
Steel Sample ◽  
Sacrificial Anode ◽  
Sacrificial Anodes ◽  
Oil Pipelines ◽  
Protection Potential ◽  
Pass Through ◽  
Selection Of

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.

Stress Corrosion Crack Initiation in X-65 Pipeline Steel Under Disbonded Coating With Cathodic Protection

2008 ◽  
Author(s):  
Bingyan Fang ◽  
Abdoulmajid Eslami ◽  
Richard Kania ◽  
Robert Worthingham ◽  
Jenny Been ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Cathodic Protection ◽  
Pipeline Steel ◽  
Seasonal Fluctuation ◽  
General Corrosion ◽  
Cathodic Current ◽  
Pipe Surface ◽  
Neutral Ph ◽  
Wide Range ◽  
Disbonded Coating

A novel testing setup has been used in this study to simulate crack initiation in X65 pipeline steel exposed to near-neutral pH soil environment. This test setup was designed to simulate synergistic interactions of cathodic current with soil environments underneath the disbonded coating on the pipe surface. It was found from the simulations that the local environment underneath the disbonded coating can be very acidic or alkaline, instead of near-neutral pH as commonly believed, depending on seasonal fluctuation in CO2 level and cathodic current. There exists a wide range of corrosion conditions on the steel surface up the gradient of cathodic current underneath the disbonded coating. General corrosion was found to increase as CP current diminishes. Pitting corrosion in terms of number of pits and size of pits was found to be the most severe at locations where cathodic protection was nearly diminished. These locations had also developed some crack like-defects, which were usually elongated in a direction perpendicular to the loading axis and appeared to be formed from a linkage of neighboring pits and by enhanced corrosion at stress raisers.

Waves on a stream of finite depth which has a velocity defect near the free surface

1970 ◽  
Vol 41 (3) ◽  
pp. 509-521 ◽  
Author(s):  
P. L. Betts
Keyword(s):  
Free Surface ◽  
High Speed ◽  
Surface Profile ◽  
Finite Depth ◽  
Simplified Model ◽  
Stationary Waves ◽  
Two Dimensional ◽  
Dimensional Theory ◽  
Velocity Defect ◽  
A Current

The conditions under which stationary waves may exist on a stream of water of finite depth are investigated theoretically for the case of a current which is uniform except for a constant defect in velocity in a region near the free surface. The analysis is extended to provide a two-dimensional theory for the surface profile induced by a simplified model of a hovering craft. The relevance of this work to the use of high speed flumes is discussed, and an example demonstrates the importance of the velocity distribution near the free surface.

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