Evaluation of the Corrosion Resistance of Steel Coated with Zinc Using a Cr-free Coating Solution as a Function of Heat Treatment Time

J. Ocean Eng. Technol. 2010;24(5):67-74.

Seo Hyun-Soo,Moon Hee-Joon,Kim Jong-Soon,Ahn Seok-Hwan,Moon Chang-Kwon,Nam Ki-Woo

Defence Agency for Technology and Quality,Graduate School Pukyong National University,NGE Tech Ltd,Bukyong Education Center for Vehicle Safety Component Technology Pukyong National University,Materials Science and Engineering Pukyong National Universit

Cr-free 코팅액에 의한 아연도금강판의 건조시간에 따른 내식특성

서현수,문희준,김종순,안석환,문창권,남기우

국방기술품질원,부경대학교 대학원,엔지텍,부경대학교 수송기계안전편의융합부품소재인재양성센터,부경대학교 신소재공학부,부경대학교 신소재공학부

Keywords: Organic/inorganic hybrid, Electrolytic Galvanized, Hot-dip Galvanized, Salt spray test, Coating solution, White rust, Heat treatment time

핵심용어: 유/무기 하이브리드, 전기아연도금, 용융아연도금, 염수분무시험, 코팅액, 백청, 열처리 시간

Abstract

Chromate conversion coating is a coating technique used to passivate aluminum, zinc, cadmium, copper, silver, magnesium, tin, and their alloys to slow corrosion. The process uses various toxic chromium compounds, which may include hexavalent chromium. The industry is developing less toxic alternatives in order to comply with substance restriction legislation, such as RoHS. One alternative is to develop a Cr-free coating solution. In this study, eco-friendly, Cr-free solutions (urethane solution S-700, organic/inorganic solution with Si LRO-317) were used. Test specimens were dried in a drying oven at $190^{circ}C$ for 3, 5, 7, and 9 minutes. Corrosion resistance was evaluated using a salt spray test for 72 hours. The results show that the optimum corrosion resistance was achieved at $190^{circ}C$ for five minutes for EGI and three or five minutes for HDGI, respectively. The adhesive properties of the two types of coating solutions were superior regardless of drying time.