Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (45권5호 198-205)

Corrosion Characteristics of the Sulfuric Acid Anodized Film Formed on Al6070 Alloy in Nitric Acid Vapor Environment

질산가스분위기에서 황산 양극산화 피막처리된 Al6070 합금의 부식특성

장일호;정도영;국진선;
Chang, Il Ho;Jung, Do Young;Gook, Jin Seon;

국방기술품질원;(주)한화 여수사업장;한려대학교 방사선학과;
Defense Agency for Technology and Quality;Yeosu Factory, Hanwha Corporation;Department of Radiology, Hanlyo University;

DOI : 10.5695/JKISE.2012.45.5.198

Abstract

The corrosion properties of anodized films on aluminium 6070 alloy in a sulfuric acid have been studied. Comparison to evaluate the anodized A6070 and pure 6070 specimen, corrosion tests in $HNO_3$ vapor environment of the 20 wt.% were performed up to 72 hours. Characteristics of film formation and surface morphology were examined by optical microscopy, FE-SEM, and EDS. The oxide film anodized in the sulfuric acid solution contained 5 to 10 wt.% of sulfur. In the initial stages of corrosion, anodized specimens exhibited corrosion resistance than the pure specimen. However, the corrosion conditions in 24 hours, corrosion was far more anodized specimen than pure specimen. Therefore, anodized films contained sulfur, nitric acid vapor in the environment is thought to stimulate corrosion.

Keywords

Sulfuric acid;Anodized films;Al6070 alloy;Nitric acid vapor;Corrosion;