文献类型：期刊文献

英文题名：Hydrogen-associated decohesion and localized plasticity in a high-Mn and high-Al two-phase lightweight steel

作者：Dong, Xizhen[1];Wang, Dong[2];Thoudden-Sukumar, Prithiv[1];Tehranchi, Ali[1];Ponge, Dirk[1];Sun, Binhan[1,3,4];Raabe, Dierk[1]

机构：[1]Max Planck Inst Eisenforsch GmbH, MaxPlanck Str 1, D-40237 Dusseldorf, Germany;[2]Norwegian Univ Sci & Technol, Dept Mech & Ind Engn, Richard Birkelands vei 2B, N-7491 Trondheim, Norway;[3]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[4]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

年份：2022

卷号：239

外文期刊名：ACTA MATERIALIA

收录：;EI(收录号：20223912785530);WOS:【SCI-EXPANDED(收录号:WOS:000856724000001)】；

语种：英文

外文关键词：Hydrogen embrittlement; Two-phase lightweight steels; Hydrogen-associated decohesion; Hydrogen-associated localized plasticity

摘要：Advanced lightweight high-strength steels are often compositionally and microstructurally complex. While this complex feature enables the activation of multiple strengthening and strain-hardening mech-anisms, it also leads to a complicated damage behavior, especially in the presence of hydrogen (H). The mechanisms of hydrogen embrittlement (HE) in these steels need to be properly understood for their successful application. Here we focus on a high-Mn (-20 wt.%), high-Al (-9 wt.%) lightweight steel with an austenite (-74 vol.%) and ferrite (-26 vol.%) two-phase microstructure and unravel the interplay of H-related decohesion and localized plasticity and their effects on failure. We find that HE in this alloy is driven by both, H-induced intergranular cracking along austenite-ferrite phase boundaries and H-induced transgranular cracking inside the ferrite. The former phenomenon is attributed to the mechanism of H -enhanced decohesion. For the latter damage behavior, systematic scanning electron microscopy-based characterization reveals that only parts of the transgranular cracks inside ferrite are straight (-52% pro-portion) and along the cleavage plane. Other portions of these transgranular cracks show a distinct devi-ation from the {100} planes at certain stages of crack propagation, which is associated with a mechanism transition from the H-enhanced transgranular decohesion of the ferrite by cleavage to the H-associated localized plasticity occurring near the propagating crack tip. These mechanisms are further discussed based on a detailed comparison to the damage behavior at cryogenic temperatures and on the nanoin-dentation results performed with in-situ H-charging. The findings provide new insights into the under-standing of the interplay between different HE mechanisms operating in high-strength alloys and their synergistic effects on damage evolution.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.