Burn Damage 온도에 따른 Epoxy Paint의 방청성 평가

Abstract

In making blocks for building offshore plants and ships, it has been generalized to do painting after finishing the outfitting work just before mounting. However, a correction part may take place during material input due to the delay of outfit materials, defect repairing, welding omission, etc. As a result, after painting work is completed for the outer plate of the hull, additional welding work has to be done on the inner plate. Then, a painting defect can be caused by the effect of burn damage on the other side of the welding part where painting work has already been finished. Currently for burn damage on a painted surface, the ship owner or the register requests a repair work after re‐docking, and this results in an additional cost. A defect caused by burn damage involves various variables including welding speed, material, heat input, temperature on the other side, and the worker’s skill. Of these variables, material is a fixed variable rather than a mechanical property or the worker’s skill, and the thickness and temperature of material play a significant role in the effect of burn damage. Recently, materials are setting thinner for the light weight of ships. If a painting defect caused by burn damage is visible with the naked eye it has to be repaired, but if not, quantitative research data are necessary. A long‐term purpose of painting is the prevention of corrosion. For this reason, it is required to analyze long‐term data on corrosion prevention according to the effect of burn damage on painted surface. This study was conducted in order to examine the effect of burn damage and resultant anti‐corrosion performance. The breakdown and defect of paint film caused by burn damage are considered to affect not only macroscopically but also the adhesive force and anti‐corrosion performance of the paint film. The material of paint film was epoxy paint that is used most widely for heavy‐duty coating, and in order to prepare burn damage, heat treatment using a torch was applied to the other side of painting. Surface and chemical structure charge according to aging was analyzed using measuring FE‐SEM and using infrared absorption spectroscopy, and variation in anti‐corrosion performance was analyzed through AC impedance test. Keywords : Burn damage, temperature, FT-IR, EIS, anti-corrosion evaluation, epoxy paint.