한국재료학회지 제28권 제7호 (p.428-434)

중성의 염화물 환경 내 자동차용 초고강도강의 부식반응에 기인한 수소원자의 발생 및 투과 메커니즘

Mechanistic Studies on the Hydrogen Evolution and Permeation of Ultra-Strong Automotive Steel in Neutral Chloride Environments
키워드 :
automotive steel,corrosion,hydrogen diffusion,permeation,chloride environment

목차

Abstract
1. 서 론
2. 실험 방법
  2.1 시험 준비
  2.2 미세조직 분석
  2.3 수소 투과 실험
  2.4 침지실험 및 XRD 분석
  2.5 Slow strain rate tensile(SSRT) 실험 및 파단면 관찰
3. 결과 및 고찰
  3.1 미세조직 분석
  3.2 수소 투과 거동 분석
  3.3 부식거동 분석
  3.4 SSRT 및 파단면 관찰
4. 결 론
References

초록

Hydrogen evolution on a steel surface and subsequent hydrogen diffusion into the steel matrix are evaluated using an electrochemical permeation test with no applied cathodic current on the hydrogen charging side. In particular, cyclic operation in the permeation test is also conducted to clarify the corrosion-induced hydrogen evolution behavior. In contrast to the conventional perception that the cathodic reduction reaction on the steel in neutral aqueous environments is an oxygen reduction reaction, this study demonstrates that atomic hydrogen may be generated on the steel surface by the corrosion reaction, even in a neutral environment. Although a much lower permeation current density and significant slower diffusion kinetics of hydrogen are observed compared to the results measured in acidic environments, they contribute to the increase in the embrittlement index. This study suggests that the research on hydrogen embrittlement in ultra-strong steels should be approached from the viewpoint of corrosion reactions on the steel surface and subsequent hydrogen evolution/diffusion behavior.