Lee, Chul-Hwan
(R&D center, Hyundai Heavy Industries, Co., Ltd.)
,
Shin, Chil-Seok
(R&D center, Hyundai Heavy Industries, Co., Ltd.)
,
Lee, Ho-Il
(R&D center, Hyundai Heavy Industries, Co., Ltd.)
,
Chung, Mong-Kyu
(R&D center, Hyundai Heavy Industries, Co., Ltd.)
,
Baek, Kwang-Ki
(R&D center, Hyundai Heavy Industries, Co., Ltd.)
Pre-construction primer (PCP), or shopprimer, have been applied to steel plates to control temporary corrosion during ship fabrication. For surface preparation at ship block stage, in common shipyard practices, welding beads, burnt and rusted areas shall be blasted or power tool cleaned and the cont...
Pre-construction primer (PCP), or shopprimer, have been applied to steel plates to control temporary corrosion during ship fabrication. For surface preparation at ship block stage, in common shipyard practices, welding beads, burnt and rusted areas shall be blasted or power tool cleaned and the contamination such as zinc salt shall be removed with blasting or power tool. Whereas, the sound film of PCP needs not to be removed or roughened as the paint having good compatibility with PCP is used for the first coat. In many cases, however, full blasting or sweep blasting on the sound PCP treated block assemblies was requested. There still has been argument about the legitimacy of this practice, thus, it is critical to evaluate the quality of the coating system applied on the sound PCP retained condition, comparing with the one applied on the full blasted or sweep blasted condition. In this study, two different epoxy systems for water ballast tank were applied on the surfaces with sound PCP condition, full blasted condition, and sweep blasted condition. Coating performances such as durability, anti-corrosion, cathodic disbondment resistance were evaluated. The test results clearly indicated that the sound film of PCP needed not to be removed or roughened as the paint having good compatibility with PCP based on inorganic zinc silicate.
Pre-construction primer (PCP), or shopprimer, have been applied to steel plates to control temporary corrosion during ship fabrication. For surface preparation at ship block stage, in common shipyard practices, welding beads, burnt and rusted areas shall be blasted or power tool cleaned and the contamination such as zinc salt shall be removed with blasting or power tool. Whereas, the sound film of PCP needs not to be removed or roughened as the paint having good compatibility with PCP is used for the first coat. In many cases, however, full blasting or sweep blasting on the sound PCP treated block assemblies was requested. There still has been argument about the legitimacy of this practice, thus, it is critical to evaluate the quality of the coating system applied on the sound PCP retained condition, comparing with the one applied on the full blasted or sweep blasted condition. In this study, two different epoxy systems for water ballast tank were applied on the surfaces with sound PCP condition, full blasted condition, and sweep blasted condition. Coating performances such as durability, anti-corrosion, cathodic disbondment resistance were evaluated. The test results clearly indicated that the sound film of PCP needed not to be removed or roughened as the paint having good compatibility with PCP based on inorganic zinc silicate.
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문제 정의
This study was performed to evaluate coating protective performance on the effect of retaining PCP. Coating performances such as durability, anti-corrosion resistance, cathodic disbondment resistance were evaluated.
가설 설정
. Adhesion strength and flexibility before and after aging coating were not affected by blasting condition.
제안 방법
) environment to simulate the water ballast tank environment. Coating performance evaluation, including adhesion strength, flexibility, anti-corrosion, and cathodic disbondment resistance, was carried out before and after aging coatings under test conditions and compared with each evaluation result. The details of test methods and conditions were shown in Table 4, along with the related standards.
on the effect of retaining PCP. Coating performances such as durability, anti-corrosion resistance, cathodic disbondment resistance were evaluated. The following conclusions were obtained from the results;
Test conditions were divided into ① immersion environment (natural seawater, 40℃)② cyclic wet(immersion, natural seawater, 40C) and dry(room temp.) environment to simulate the water ballast tank environment. Coating performance evaluation, including adhesion strength, flexibility, anti-corrosion, and cathodic disbondment resistance, was carried out before and after aging coatings under test conditions and compared with each evaluation result.
On the other hand, Erischen Cupping test (ISO 1520) is generally resulted in gradual deformation by indentation. Therefore, in this study, modified Erischen cupping test method was adopted to evaluate coating flexibility. Since the crack initiation point is the most important in the flexibility evaluation of coatings, the crack initiation depth was measured by visual examination, advancing the indenter into the test specimen to verify the depth of indentation at crack initiation point on the coating surface.
Therefore, in this study, the effect of retaining sound PCP on the coating performance comparing with sweepblasted condition and full blasted condition was investigated.
성능/효과
Comparing with R of applied coating systems after cathodic disbondment test for 6 months, it was indicated that cathodic disbondment resistance of coating system N was superior to that of coating system H approximately 3 to 5 times and was little aflfected by surface preparation condition. However, cathodic disbondment resistance of coating system H in full blasted condition was higher than in sweep blasted condition and sound condition.
참고문헌 (7)
KOSHIPA, The Shipbuilders' Painting and Inspection Practice, p.13- 15 (2005)
ISO 20340, Paints and varnishes-Performance Requirements for Protective Paint Systems for Offshore and Related Structures (2003)
IMO DE 49/WP3, Performance Standards for Protective Coatings (2006)
C. G. Munger and L. D. Vincent, p. 63, NACE International, (1999)
C. H. Lee, HHI Technical Report_HIRI 04AB204, p. 25 (2006)
R. W. Drisko, et. aI., Corrosion & Coatings: An Introduction to Corrosion for Coatings Personnel, SSPC, p. 5I (1998)
O. O. Knudsen, E. Bardal, and U. Steinsmo, JCSE, 12, 13 (1999)
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