Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (46권5호 229-233)

An Analysis of Small Punch Test Conducted with the High Strength Dual Phase Sheet Steels Charged with Hydrogen

수소주입된 고강도 DP 박강판의 소형펀치시험결과 분석

최영철;박재우;강계명;
Choi, Young-Cheul;Park, Jae-Woo;Kang, Kae-Myung;

서울과학기술대학교 산업대학원 재료공학과;서울과학기술대학교 에너지환경대학원 신에너지공학과;서울과학기술대학교 신소재공학과;
Dept. of Materials Science & Engineering, Graduate School of Industry & Engineering, Seoul National University of Science & Technology;Dept. of New Energy Engineering, Graduate School of Energy & Environment, Seoul National University of Science & Technology;Dept. of Materials Science & Engineering, Seoul National University of Science & Technology;

DOI : 10.5695/JKISE.2013.46.5.229

Abstract

The small punch(SP) tests that can be applied to high strength sheet steel in automobile were carried out to evaluate the behavior of hydrogen embrittlement of DP sheet steels. In order to charge hydrogen at DP sheet steels, DP sheet steels were treated by the electrochemical hydrogen charging method under the charging conditions of current densities of 100, 150 and 200 $mA/cm^2$ for charging times of 5, 10, 25 and 50 hrs. Respectively, After hydrogen charging with experimental conditions, SP tests were performed. From the SP results, the correlations between the variation of bulb diameters and bulb heights with the hydrogen charging conditions were analysed. It was shown that the variation of bulb diameters were not significant with the hydrogen embrittlement due to the amounts of hydrogen charging. On the other hand, the bulb heights were observed to decrease with increasing hydrogen contents. It was thought that these results of the variation of bulb shapes after SP tests would be estimated as the index of evaluation of hydrogen embrittlement.

Keywords

Hydrogen embrittlement;SP test;DP sheet steels;Hydrogen charging;