文献类型：期刊文献

英文题名：Mitigating Hydrogen-Induced and Cryogenic Embrittlement via Interfacial Boron Segregation in Austenitic Lightweight Steel ?

作者：Elkot, Mohamed Naguib[1,3]; Kumar, Sourabh[2]; Saksena, Aparna[1]; Sun, Binhan[4,5]; Hickel, Tilmann[2]; Ponge, Dirk[1]; Raabe, Dierk[1]

机构：[1] Max Planck Institute for Sustainable Materials, Max-Planck-Stra?e 1, Düsseldorf, 40237, Germany; [2] Federal Institute of Materials Research and Testing [BAM], Berlin, 12489, Germany; [3] Department of Metallurgical and Materials Engineering, Suez University, Suez, 43512, Egypt; [4] Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China; [5] State Key Laboratory of Chemical Safety, East China University of Science and Technology, Shanghai, 200237, China

年份：2026

外文期刊名：SSRN

收录：EI(收录号：20260319659)

语种：英文

外文关键词：Adhesion - Aluminum alloys - Atoms - Austenite - Boron - Brittle fracture - Cryogenics - Ductile fracture - Ductility - Hydrogen storage - Hydrogen storage alloys - Manganese alloys - Segregation (metallography) - Tensile strength

摘要：Lightweight, high-strength steels and parts made from them for low-temperature hydrogen storage and transport must have tolerance to hydrogen-rich and cryogenic conditions, as well as resistance to the associated microstructural damage mechanism. Here, we explore boron doping as a strategy to mitigate intergranular failure in austenitic high-Mn, high-Al lightweight steel under hydrogen exposure and at cryogenic temperatures down to -196°C. A tailored heat treatment promotes boron segregation to grain boundaries in the solute state (i.e., without boride formation), as verified by site-specific atom probe tomography (APT). The effects of boron on mechanical performance were evaluated through tensile testing with and without in-situ hydrogen charging, Charpy impact testing at room temperature and down to -196°C, and thermal desorption spectroscopy (TDS). We reveal that boron doping markedly suppresses intergranular cracking, reducing hydrogen-induced ductility loss from 38% to 8% at room temperature and shifts the ductile-to-brittle transition temperature from -62°C to -155°C. DFT calculations indicate that boron enhances GB cohesive strength by 0.84 eV per atom, while hydrogen weakens GB by 0.40 eV per atom. Co-segregation of a B-H pair still results in a net increase of cohesion of 0.47 eV/pair. While enhanced GB cohesion emerges as the dominant mechanism, additional contributions to the improved mechanical performance, including reduced hydrogen solubility and diffusivity at GBs, as well as improved slip transmission across GBs, are also discussed. These findings establish boron doping as a key mechanism-informed approach for enhancing GB cohesion and resistance to hydrogen embrittlement in FCC alloys. ? 2026, The Authors. All rights reserved.