Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (46권1호 42-47)

Hydrogen Delayed Fracture of TRIP Steel by Small Punch Test

소형펀치시험에 의한 TRIP강의 수소 지연파괴 거동

최종운;박재우;강계명;
Choi, Jong-Un;Park, Jae-Woo;Kang, Kae-Myung;

서울과학기술대학교 신소재공학과;서울과학기술대학교 에너지환경대학원 신에너지공학과;
Department of Materials Science and Engineering, Seoul National University of Science & Technology;Department of New Energy Engineering, Graduate School of Energy & Environment, Seoul National University of Science & Technology;

DOI : 10.5695/JKISE.2013.46.1.042

Abstract

The strain-induced phase transformation from austenite to martensite is responsible for the high strength and ductility of TRIP steels. However high strength steels are susceptible to hydrogen embrittlement. This study aimed to evaluate the effects of hydrogen on the behavior of hydrogen delayed fracture in TRIP steel with hydrogen charging conditions. The electrochemical hydrogen charging was conducted at each specimen with varying current density and charging time. The relationship between hydrogen concentration and mechanical properties of TRIP steel was established by SP test and SEM fractography. The maximum loads and displacements of the TRIP steel in SP test decreased with increasing hydrogen charging time. The results of SEM fractography investigation revealed typical brittle mode of failure. Thus it was concluded that hydrogen delayed fracture in TRIP steel result from the diffusion of hydrogen through the ${alpha}$` phase.

Keywords

TRIP steel;Hydrogen embrittlement;Hydrogen delayed fracture;