수소전기차 사용소재의 수소취성 안전성에 관한 고찰

전현진,정원종,조성구,이호식,이현우,조성우,강일호,김남용,류호진 한국수소및신에너지학회 2022 한국수소 및 신에너지학회논문집 Vol.33 No.6

In the hope of realizing carbon neutrality, Korea has established the goal of expanding the supply of hydrogen electric vehicles through a roadmap to revitalize the hydrogen economy. A prerequisite for successful supply expansion is securing the safety of hydrogen electric vehicles. Certain parts, such as the hydrogen transport pipe and tank, in hydrogen electric vehicles are exposed to high-pressure hydrogen gas over long periods of time, so the hydrogen enters the grain boundary of material, resulting in a degradation of the parts referred to as hydrogen embrittlement. In addition, since the safety of parts utilizing hydrogen varies depending on the type of material used and its environmental characteristics, the necessity for the enactment of a hydrogen embrittlement regulation has emerged and is still being discussed as a Global Technical Regulation (GTR). In this paper, we analyze a hydrogen compatibility material evaluation method discussed in GTR and present a direction for the development of Korean-type hydrogen compatibility material evaluation methods.

Pd 코팅된 Zr기 비정질 합금의 수소취성 및 표면특성

석송,이덕영,김기배 한국수소및신에너지학회 2007 한국수소 및 신에너지학회논문집 Vol.18 No.2

Zr50-Ni27-Nb18-Co5 amorphous alloys ribbon was prepared by a single-roller melt-spinning technique. In order to improve the hydrogen kinetics Pd-coating were carried out on each side of the amorphous ribbon. Pd prevents oxidation of Zr and catalyses the dissociation of molecular hydrogen to atomic hydrogen. In this work, the hydrogen embrittlement and surface properties on Zr-based amorphous alloys were investigated. The Zr-based amorphous alloys were characterized by X-ray diffractometry(XRD) and differential scanning calorimetry(DSC). The morphology of surface and roughness was observed by using scanning electron microscopy(SEM) and atomic force microscopy (AFM). A lattice parameter of both Pd and Zr-based amorphous alloy was increased after hydrogen permeation at 473 K. After hydrogen permeation at 473 K, some cracks were observed on the surface of Pd, which was the cause for the hydrogen embrittlement. The crystallization temperature of Zr-based amorphous alloy was decreased due to the permeated hydrogen.

삼중수소 저장용기 이종용접부의 수소취화 거동 평가 (Ⅱ)

조경원,최재하,장민혁,이영상,홍태환 한국수소및신에너지학회 2015 한국수소 및 신에너지학회논문집 Vol.26 No.2

Recently, the ever-increasing use of fossil fuels for rapid industrial development and population significantly caused an environment pollution and global warming such as climate change. So research and development of sustainable and eco-friendly energy have been performed. Especially the interest in nuclear fusion fuel was significantly increased from the developed countries. The system of fusion energy production was tritium separation, storage and delivery, and purification. Republic of Korea is in charge of Storage and Delivery System (SDS) in the International Thermonuclear Experimental Reactor (ITER). Welding part of the SDS bottles for storing the tritium is known to be susceptible to hydrogen embrittlement. In this study, conducted a study for the relaxation of the stability and hydrogen embrittlement of the weld area. The hydrogen heat treatment was processed through the Pressure-Composition-Temperature (PCT) device according to the time variation. Also mechanical properties such as impact test and hardness test according to using the alkaline cleaning liquid for hydrogen embrittlement relief and the fracture was observed by scanning electron microscopy (SEM) after the mechanical properties evaluation.

수소 장입된 극저온용 철강 소재의 수소 취화 특성 평가 Part I : 수소 장입량 비교

김재웅,김성환 한국기계기술학회 2021 한국기계기술학회지 Vol.23 No.5

Due to global warming and environmental pollution, environmental regulations are getting stronger, and the International Maritime Organization announced regulations to reduce CO2 emissions in 2018. In order to respond to this, interest in hydrogen energy is growing, and research on liquid hydrogen is spotlighted for storage and transport of large amounts of hydrogen. Hydrogen reduces in volume to 1/800 when liquefied, but its boiling point is close to absolute zero(-253°C), and hydrogen embrittlement that penetrates other materials and weakens mechanical properties. In this study, the change of mechanical properties under cryogenic conditions (-196 degrees below zero) was confirmed after charging hydrogen into existing cryogenic materials (Stainless steel, High Manganese steel, 9% Nickel steel). In Part I, hydrogen was charged using an electrochemical method and quantitative evaluation was performed. In all four materials, as the changing time increased, the diffusible hydrogen concentration increased. After 24 hours charging, the hydrogen loading of 20 wppm in 9% Ni steel and 15 wppm in high-Mn steel was confirmed. In a follow-up study, we plan to study the effect of hydrogen charging by comparing the results of the mechanical properties test with the above results.

수소배관 운영 조건에 따른 배관강이 수소취성에 미치는 영향 인자 분석

백종현(JONGHYUN BAEK),장윤찬(YUNCHAN JANG),김철만(CHEOLMAN KIM) 한국수소및신에너지학회 2024 한국수소 및 신에너지학회논문집 Vol.35 No.2

Pipeline steels for hydrogen transmission may cause hydrogen embrittlement due to absorption and diffusion of hydrogen through metals. Hydrogen pipes exhibited similar mechanical properties to atmospheric conditions in terms of tensile and yield strength in a hydrogen atmosphere. This paper aims to provide relevant information regarding hydrogen embrittlement in hydrogen transmission pipeline.

특수합금 사각봉 모넬 소재의 탄성영역 인발특성 해석

양영준 한국기계기술학회 2022 한국기계기술학회지 Vol.24 No.4

Hydrogen gas is usually used in many industrial facilities, for instance, such as semiconductor, vehicle and gas station. Because hydrogen embrittlement leads to the big damages in bolts, nut, especially, high pressure valves with common materials, therefore, special alloy including Monel material is recommended to reduce the hydrogen embrittlement. The purpose of this study is to investigate the characteristics of Monel within elastic limit through numerical analysis when Monel is drawn by drawing system. As the results, it showed that safety factor was decreased, but deformation and stress was increased, when the number of pass was increased. Furthermore, the method for designating work hardening in numerical simulation was needed to achieve the exact solution in this study.

PEMFC 연료 공급관의 수소취성에 관한 연구

박광진(Kwangjin Park),김정현(Jung Hyun Kim),정재화(Jaehwa Jeong),배중면(Joongmyeon Bae) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

This study focuses on the hydrogen embrittlement of iron tube for fuel line of PEMFC (Proton Exchange Membrane Fuel Cell). PEMFC is operated by feed of hydrogen as a reactant and steam for proton conductivity of membrane. However, the environment with hydrogen and steam occur the hydrogen-induced degradation in BOP system. When iron tube was exposed to hydrogen and steam condition for 24 hours, the oxide layer on the surface was decreased by reduction. When the ambient temperature was 90℃, micro cracks were found on the surface than any other temperature. The mechanical strength of iron tube was 3% lower than that of non-experiment tube. Maximum tensile stress was decreased 8%.

합금속의 수소취성과 응력부식균열 고찰

김영석,임경수,정용무 한국수소및신에너지학회 2004 한국수소 및 신에너지학회논문집 Vol.15 No.4

The objective of this study is an understanding of stress corrosion cracking of metals that is recognized to mostly limit the lifetime of the structural materials by comparing the features of delayed hydride cracking of zirconium alloys with those of stress corrosion cracking (SCC) of Ni-based alloys and hydrogen cracking of stainless steels. To this end, we investigated a dependence of delayed hydride cracking (DHC) velocity on the applied stress intensity factor and yield strength, and correlated a temperature dependence of the striation spacing and the DHC velocity. We reviewed a similarity of the features between the DHC of zirconium alloys, the SCC of Ni-based alloys and turbine rotor steels, and the hydrogen cracking of stainless steels and discussed the SCC phenomenon in metals with our DHC mode

자주포 궤도 너트에 미치는 우발적 수소취성 현상의 영향

길현준(Hyeon-Jun Gil),김병호(Byeong-Ho Kim),강현제(Hyeon-Jae Kang),서재현(Jae Hyun Seo) 한국기계가공학회 2016 한국기계가공학회지 Vol.15 No.3

In this study, we analyzed the accidental hydrogen embrittlement affecting the track nut on a self-propelled howitzer. Tracks are key components to maintain a high degree of confidence in the operation of the self-propelled howitzer and the safety of the crew. This study analyzed the fractured surface using SEM to review accidental damage of the wedge nut. In addition, we conducted revival tests and analyzed the results to identify the cause of the wedge nut damage from hydrogen embrittlement. We should carry out factor analysis and continuous improvement of the manufacturing process to determine the accidental breakage mechanism for future enhancement of the self-propelled howitzer. This study will be the useful reference for enhancing process designs in similar products.

수소취성 메커니즘과 방지법에 대한 연구

강수영,최형일 한국기계기술학회 2022 한국기계기술학회지 Vol.24 No.4

Hydrogen embrittlement refers to a phenomenon in which the ductility and toughness of steel materials are lowered by hydrogen absorbed in metal materials, especially steel, and the tendency to fracture without plastic deformation increases. Fracture due to hydrogen absorption is also called delayed fracture, and it mainly occurs at grain boundaries, stress concentration areas, or areas subject to tensile stress. From a practical point of view, hydrogen embrittlement is frequently associated with corrosion, welding, pickling, electroplating, etc., and in materials, it is prominently displayed in stainless steel or high tensile steel. Regarding the embrittlement mechanism, there is no generally accepted orthodoxy. In this study, A hydrogen embrittlement mechanism is proposed. In addition, the method of suppressing hydrogen embrittlement will be considered.