• Journal of Power System Engineering
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• v.8 no.3
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• pp.44-51
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• 2004

Effect of corrosion characteristics in relation to loaded stress in the welded zone of A5083-H116 aluminum alloy, in the seawater was studied. The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded stress. The corrosion crack, corrosion rate, electrode potential, current, and corrosion pattern, etc. were examined for the specimens with the elapse of the immersion time. The main result derived from this study is the crack growth length is increased with the increasing loaded stress. The electrode potential and the corrosion current are decreased rapidly in the early stage of the corrosion, and then decreased gradually and stabilized eventually with the elapse of the immersion time. The test condition of the longer crack growth tends to show the higher corrosion rate. Corrosion pattern of the welded zone indicates that the depth and width of the pitting become increasing with the increasing loaded stress.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.537-542
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• 2002

The social trouble to the durability of concrete rises recently because the embedded rebar corrosion influences concrete structures to deteriorate structural capacity. And also, the rebar corrosion causes crack of concrete, decrease of steel section and separation of covering concrete. In the result, the bond strength of concrete and embedded rebar decreases, which causes deterioration of the structure behavior in reinforced concrete. In this study, the relation of bond strength and bond-slip was understood to evaluate capacity deterioration of reinforced concrete, and experiments were carried out by compressive strength and embedded rebar condition in the rebar corrosion rate.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.178-179
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• 2014

Corrosion is very serious problem in RC structure under ocean environment. There is no enough experiment information using the reinforced geo polymer concrete applied by electo chemical protection system. Three condition, such as tidal zone, submerged zone and crack were simulated to geo polymer specimen. Corrosion rate and natural electrode potential were measured through accelerated test. Anti corrosion property of geo polymer was better than OPC regardless of specimen condition and applied time.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.232-233
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• 2014

Recently, water treatment facility is usually eastablished in underground, and waterproofing and anti-corrosion materials for concrete structures applied water treatment tank is developing in various ways. However, as the limit of research focused on durability improvement of top coating material, it is insufficient to study on the adhesion strength between the concrete surface and primer. Therefore, there is to confirm the adhesion of between concrete surface and the three primers used as anti-corrosion waterproofing materials, and to investigate the properties of adhesion strength according to the condition such as wet codition and water pressure condition of the concrete surface in this study.

• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.239-248
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• 2004

Likelihood of failure for the external corrosion of carbon and low alloy steels, which affect to a risk of facilities, was analyzed quantitatively through the risk based inspection using API-581 BRD. We found that the technical module subfactor (TMSF) decreased as the inspection number increased and it increased as the Inspection effectiveness and the used year increased. In this condition, the TMSF showed high value for the case of the marine/cooling tower drift area as a corrosion driver, poor quality of coating, no insulation, and low insulation condition.

• Journal of the Korea Safety Management & Science
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• v.5 no.1
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• pp.129-141
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• 2003

In this thesis, using the 400 series ferrite stainless steel such as 434LD$_2$ which are furter excellent then the existing ferric products in mechanical characteristics, and experiment has been conducted on corrosion resistance of sensor ring. The results are following. 1. The products before sintering are much more corrodible in the condition of spray test of salt water and ammonia than humidity and nitrogen condition. 2. 434LD$_2$ ferrite stainless steel has shown a good corrosion resistance without an addition surface treatment. thus the decreasing production process has been obtained. 3. As hardness value of $H_{RB}$ 80 and tensile test, 434LD$_2$ ferrite stainless steel with show a good endurance when it is combined to constant velocity joint (c/v joint), and has a good hardness properties endurable to sand and pebble impact.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.16-24
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• 2019

The corrosion amounts of steel structures can be different depending on their installation condition and height. Thus, their corrosion maintenance should be considered depending on installation conditions of local structural members. In this study, an atmospheric exposure test was conducted to evaluate the corrosion amount and the corrosion rate depending on the installation condition and height of a steel water gate using monitoring steel plates and corrosion environment measuring sensors. The mean corrosion depth was evaluated using the weight loss method and the galvanic corrosion current was measured by corrosion environment measuring sensors. Local corrosion rate of local structural member in steel water gate was estimated using measured mean corrosion depths and galvanic corrosion currents. From this measurement results, the corrosion damage in horizontal member of the cross beam was highly evaluated than those of other structural member as skin plate, etc. The relative difference in the corrosion rate of a local structural member could be highly affected by local corrosion environments of steel water gate members. Therefore, an appropriate maintenance method should be considered for local corrosion damages of local structural members determined by local corrosion environments of a steel water gate.

• Corrosion Science and Technology
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• v.15 no.1
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• pp.18-27
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• 2016

In this study, the accelerated corrosion test by combined deteriorating action of salt damage and freeze-thaw was investigated. freeze-thaw cycle is one method for corrosion testing; corrosion initiation time was measured in four types of concrete samples, i.e., two samples mixed with fly ash (FA) and blast furnace slag (BS), and the other two samples having two water/cement ratio (W/C = 0.6, 0.35) without admixture (OPC60 and OPC35). The corrosion of rebar embedded in concrete occurred most quickly at the $30^{th}$ freeze-thaw cycle. Moreover, a corrosion monitoring method with a half-cell potential measurement and relative dynamic elastic modulus derived from resonant frequency measures was conducted simultaneously. The results indicated that the corrosion of rebar occurred when the relative dynamic elastic modulus was less than 60%. Therefore, dynamic elastic modulus can be used to detect corrosion of steel bar. The results of the accelerated corrosion test exhibited significant difference according to corrosion periods combined with each test condition. Consequently, the OPC60 showed the lowest corrosion resistance among the samples.

• Corrosion Science and Technology
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• v.17 no.6
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• pp.310-316
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• 2018

The effect of passive film on corrosion of metals and alloys in a static corrosive environment has been studied by many researchers and is well known, however few studies have been conducted on the electrochemical measurement of metals and alloys during cavitation corrosion conditions, and there are no test standards for electrochemical measurements 'During cavitation' conditions. This study used commercially additive manufactured(AM) pure titanium in tests of anodic polarization, corrosion potential measurements, AC impedance measurements, and repassivation. Tests were performed in 3.5% NaCl solution under three conditions, 'No cavitation', 'After cavitation', and 'During cavitation' condition. When cavitation corrosion occurred, the passive current density was greatly increased, the corrosion potential largely lowered, and the passive film revealed a small polarization resistance. The current fluctuation by the passivation and repassivation phenomena was measured first, and this behavior was repeatedly generated at a very high speed. The electrochemical corrosion mechanism that occurred during cavitation corrosion was based on result of the electrochemical properties 'No cavitation', 'After cavitation', and 'During cavitation' conditions.

• Journal of the Korea Concrete Institute
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• v.12 no.3
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• pp.21-30
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• 2000

Recently, reinforced concrete structures exposed to severe enviroment are increased in metropolitan area. The acid rain and CO2 penetrated towad rebar, thus rebar corrosion occurred. The corrosion of rebar in concrete is, as in most corrosion processes, an electrochemical nature. The corrosion may severely affect on durability and service life of such a concrete structures. This study was performed for the purpose of acquiring data about corrosion condition and considering a countermeasure to prevent rebar from corroding due to carbonation of concrete. An accelerated car bonation testing procedure was applied to measure the evolution of carbonation and rebar corrosion with time for various water-binder ratios and cement types.