• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.373-378
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• 2000

The crevice corrosion of local corrosion occur when the gap exist on metal surface. This crevice corrosion happen to region such as flange of pipe, contact part of casing, under gasket and packing, between valve disk and seat of pump etc. Especially The crevice corrosion of mild steel(SS 400) get serious. This paper was studied on the crevice corrosion of SS 400 in fluid environment. In $0\%,\;2\%,\;3.5\%,\;5\% NaCl$ solution, the aspect of the crevice corrosion and polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 with crevice and non-crevice was measured according to the NaCl concentration. The main results obtained are as follows : 1) Under crevice corrosion, the corrosion potential become less noble as the concentration of NaCl solution increased. 2) The current density under open circuit potential was high drained as concentration of NaCl solution increased by $3.5\%$ but the concentration increased over $3.5\%$, the current density was low drained. 3) The weight loss rate of SS 400 was increased as concentration of NaCl solution Increased by $3.5\%$, but the concentration increased over $3.5\%$, that of SS 400 was decreased. 4) Effect of oxygen for crevice corrosion in the concentration of $3.5\%$ NaCl solution become sensitive than that $0\%$ NaCl solution.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.3
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• pp.447-452
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• 2003

Crevice corrosion is localized form of corrosion usually associated with a stagnant solution on the micro-environmental level. Such stagnant micro environments tend to occur in crevices (shielded areas) such as those formed under gaskets washers insulation material. fastener heads. surface deposits. disbonded coatings. threads. lap joints and clamps. Crevice corrosion is initiated by changes in located electrochemical reaction within the crevice such as a) depletion of inhibitor in the crevice b) depletion of oxygen in the crevice c) a shift to acid conditions in the crevice and d) build-up of aggressive ion species (e.g chloride) in the crevice. In this study. the mechanism of crevice corrosion for Type 430 stainless steel is investigated undercondition that the size of specimen is $15{\times}20\{times}3mm$, in 1N $H_2SO_4$ + 0.05N NaCl solution. and the artificial crevice gap size of 3 x 0.2 x 15 mm. Crevice corrosion is measured under applied potential -300mV(SCE) to the external surface. The obtained result of this study showed that 1) the induced time for initiation of crevice is 750 seconds. 2) potential of the crevice was about from -320mV to -399mV. which is lower than that of external surface potential of -300mV It is considered that potential drop in the crevice is one of mechanisms for the crevice corrosion

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.1
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• pp.106-114
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• 2005

This paper is a study on the prevention of crevice corrosion for a stainless steel heat exchanger in various pH solutions and with Cl ion concentrations. The electrochemical polarization test and crevice corrosion test of STS 304 for a heat exchanger were carried out. The crevice corrosion aspect, a passive behavior, crevice corrosion behavior, and corrosion protection characteristics of STS 304 using Al-alloy and Mg-alloy galvanic anode were considered. The main results are as follows: 1. The crevice corrosion of STS 304 occurs in the crevice and this corrosion increases pitting according to depth direction. On the other hand, the exterior crevice becomes passive. 2. With changing from a neutral to acid environment and increasing Cl ion concentration, the pitting potential of STS 304 lowers, and thus the crevice corrosion of STS 304 is sensitive. 3. The cathodic protection potential of STS 304 in the crevice is cathodically polarized by increasing Cl ion concentration. Therefore, an Al-alloy galvanic anode is more suitable than a Mg-alloy galvanic anode to protect the crevice corrosion of STS 304.

• Corrosion Science and Technology
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• v.5 no.3
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• pp.90-93
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• 2006

Prevention of crevice corrosion was studied for STS 304 stainless steel using a Mg-alloy galvanic anode in solutions with various specific resistivity. The crevice corrosion and corrosion protection characteristics of the steel was investigated by the electrochemical polarization and galvanic corrosion tests. Experimental results show that the crevice corrosion of STS 304 stainless steel does not occur in solutions of high specific resistivity, but it occurs in solutions of low specific resistivity like in solutions with resistivities of 30, 60 and $115{\Omega}{\cdot}m$. With decreasing specific resistivity of the solution, the electrode potential of STS 304 stainless steel in the crevice is lowered. The potential of STS 304 stainless steel in the crevice after coupling is cathodically polarized more by decreasing specific resistivity indicating that the crevice corrosion of STS 304 stainless steel is prevented by the Mg-alloy galvanic anode.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1336-1340
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• 2001

Due to increase of air pollution substance, such as $SO_2$,$SO_3$, H2S ,CO, HCI, $Cl_2$ and so on, the operating environment of mechanical equipment and facilities like generating plants, ships, metal structure etc., are acidified and corroded. In these environments, the crevice corrosion of marine facilities frequently occurs at crevice like jointed bolt, gasket or sealant, riveted plates, contact of metal with non-metallic solids etc. Therefore, this paper was studied on the crevice corrosion behavior of mild steel(SS 400) in marine environment. In a variety of NaCl solutions, the aspect of he .crevice corrosion and polarization behavior under the crevice corrosion was investigated. The main results obtained are as follows: 1) Under crevice corrosion, the open circuit potential become less treble as the concentration of NaCl solution increased. 2) The corrosion current density of mild steel was high drained as the concentration of NaCl solution increased by 3.5%, but in the concentration increased over 3.5%, the corrosion current density was low drained. 3) The crevice corrosion is more sensitive to the synergy effect of dissolved oxygen and NaCl.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.1-6
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• 2000

This paper was studied on the crevice corrosion behavior of SS 400 in marine environment. In 0%, 2%, 3.5%, 5% NaCl solution, the aspect of the crevice corrosion and polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 with crevice and non-crevice was measured according to the NaCl concentration. The main results obtained are as follows : 1) Under crevice corrosion, the corrosion potential become less noble as the concentration of NaCl solution increased. 2) The current density under open circuit potential was high drained as concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, the current density was low drained. 3) The weight loss rate of SS400 was increased as concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, that of SS400 was decreased.

• Journal of the Korean institute of surface engineering
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• v.40 no.2
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• pp.82-90
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• 2007

Crevice corrosion is the accelerated attack occurred in the occluded cell under a crevice on the metal surface. Crevice corrosion behaviors of nickel-based alloys such as Alloy 600 and Alloy 690 were investigated in acidic solution with different chloride ion concentrations. Tests were carried out using the specially designed crevice cell with a very narrow Luggin capillary assembly to measure the potential inside the crevice. It is believed that crevice corrosion in active/passive system like nickel-based alloys has much to do with the properties of passive film and its repassivation characteristics, investigated by the capacitance measurement and by the abrading electrode technique, respectively. An attempt was made to elucidate the relationship between crevice corrosion behaviors, properties of passive film and its repassivation kinetics. Results showed that repassivation rate parameter $n1{\leq}0.6$ and/or $n2{\leq}0.5$ indicated the possible occurrence of crevice corrosion.

• Journal of the Korean institute of surface engineering
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• v.36 no.4
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• pp.324-328
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• 2003

This study was made on the crevice corrosion behavior of chromium plating in fresh water. Under the various crevice, the electrochemical polarization test of chromium plating was carried out. Results are discussed In terms of corrosion potential, polarization resistance, corrosion current density and cathodic control of chromium plating.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.51-54
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• 2004

In recently days, the breed fish farm is increased in the beach side for farming fish. In such a farm, the heater is requested for preventing freezing in cold season. The heating material are requested high corrosion resistance and strength for endurance high corrosive salt and pressure. In case of low corrosion resistance and/or strength, the heating element shall be broke down and eventually make spillage or leaking contaminated salt. In the most cases, crevice corrosion is localized form of corrosion usually associated with a stagnant solution on the micro-environmental level. In this study, the crevice corrosion of Ferritic type 430 stainless steel is investigated. The size of specimen is $15{\times}20{\times}3mmt$. Test solution is 1N H2SO4 + 0.05N NaCl. The artificial crevice gap size is $0.24{\times}3{\times}15mmL$. Crevice corrosion is measured under applied voltage 300mV(SCE) to the external surface. the result of this study showed that 1) the induced time for initiation of crevice is 750seconds, 2) potential is dropped in the crevice from the top of gap opening from -320 to -399mV. The result confirmed that the potential drop(IR mechanism) in the crevice is one of mechanism for crevice corrosion.

• Corrosion Science and Technology
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• v.14 no.6
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• pp.288-295
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• 2015

The present work addresses crevice and galvanic corrosion processes occurring at the cylinder head gasket/cylinder head interface and cylinder head gasket/cylinder liner interface of four-stroke medium-speed diesel engines for marine applications. The contact between these systems and the marine environment can promote formation of demanding corrosion conditions, therefore influencing the lifetime of the engine components. The electrochemical behavior of various metals and alloys used as head gasket materials (both ferrous alloys and copper alloys) was investigated. The efficacy of corrosion inhibitors was determined by comparing electrochemical behavior with and without inhibitors. In particular, crevice corrosion has been investigated by electrochemical tests using an experimental set-up developed starting from the requirements of the ASTM G-192-08, with adaptation of the test to the conditions peculiar to this application. In addition to the crevice corrosion resistance, the possible problems of galvanic coupling, as well as corrosive reactivity, were evaluated using electrochemical tests, such as potentiodynamic measurements. It was possible to quantify, in several cases, the corrosion resistance of the various coupled materials, and in particular the resistance to crevice corrosion, providing a basis for the selection of materials for this specific application.