Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (47권4호 186-191)

Effect of Heat Treatment on the Corrosion Resistance of the Al-Mg Coated Steel Sheet

열처리가 Al-Mg 코팅 강판의 내식성에 미치는 영향

정재훈;양지훈;송민아;김성환;정재인;이명훈;
Jung, Jae-Hun;Yang, Ji-Hoon;Song, Min-A;Kim, Sung-Hwan;Jeong, Jae-In;Lee, Myeong-Hoon;

포항산업과학연구원 시스템솔루션연구센터;한국해양대학교;
System Solution Research Center, Research Institute of Industrial Science & Technology;Korea Maritime and Ocean University;

DOI : 10.5695/JKISE.2014.47.4.186

Abstract

Double layer films which consisted of aluminum(Al) and magnesium(Mg) have been prepared by e-beam deposition. The structure, alloy phase, and corrosion resistance of the prepared films were investigated before and after heat treatment. The first (bottom) layer fixed with Al, and the thickness ratio between Al and Mg layers has been changed from 1 : 1 to 5 : 1, respectively. Total thickness of Al-Mg film was fixed at $3{mu}m$. The cold-rolled steel sheet was used as a substrate. Heat treatment was fulfilled in an nitrogen atmosphere at the temperature of $400^{circ}C$ for 2, 3 and 10 min. Surface morphology of as-deposited Al-Mg film having Mg top layer showed plate-like structure. The morphology was not changed even after heat treatment. However, cross-sectional morphology of Al-Mg films was drastically changed after heat treatment, especially for the samples heat treated for 10 min. The morphology of as-deposited films showed columnar structure, while featureless structure of the films appeared after heat treatment. The x-ray diffraction data for as-deposited Al-Mg films showed only pure Al and Mg peaks. However, Al-Mg alloy peaks such as $Al_3Mg_2$ and $Al_{12}Mg_{17}$ appeared after heat treatment of the films. It is believed that the formation of Al-Mg alloy phase affected the structure change of Al-Mg film. It was found that the corrosion resistance of Al-Mg film was increased after heat treatment.

Keywords

Al-Mg;Physical vapor deposition;E-beam evaporation;Corrosion resistance;steel sheet;Heat treatment;