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Improving mechanical properties and high-temperature oxidation of press hardened steel by adding Cr and Si

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1865-1875页

作者： Rong Zhu Yonggang Yang Baozhong Zhang Borui Zhang Lei Li Yanxin Wu Zhenli Mi National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing 102206China Manufacturing Management Department Ningbo Iron&Steel Co.Ltd.Ningbo 315800China Hunan Valin Lianyuan Iron and Steel co. Ltd.Loudi 417009China

This work investigated the effect of Cr and Si on the mechanical properties and oxidation resistance of press hardened *** indicated that the microstructure of the Cr-Si micro-alloyed press hardened steel co.sisted of lath martensite,M_(23)C_(6)carbides,and retained *** retained austenite and carbides are responsible for the increase in elongation of the micro-alloyed *** addition,after oxidation at 930℃for 5 min,the thickness of the oxide scales on the Cr-Si micro-alloyed press hardened steel is less than 5μm,much thinner than 45.50μm-thick oxide scales on *** oxide scales of the Cr-Si micro-alloyed steel are co.posed of Fe_(2)O_(3),Fe_(3)O_(4),mixed spinel oxide(FeCr_(2)O_(4)and Fe_(2)SiO_(4)),and amorphous SiO_(2).Adding Cr and Si significantly reduces the thickness of the oxide scales and prevents the generation of the FeO *** to the increase of spinel FeCr_(2)O_(4)and Fe_(2)SiO_(4)phase in the inner oxide scale and the amorphous SiO_(2)close to the substrate,the oxidation resistance of the Cr-Si micro-alloyed press hardened steel is improved.

关键词： Cr-Si micro-alloyed press hardened steel mechanical properties oxidation resistance amorphous SiO_(2)

Progress on the glassy-crystal laminates:From design,microstructure to deformation and future solutions

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Journal of Materials Science & Technology 2024年第5期172卷 113-144页

作者： Yu Chen Ronggao Cui Jun Shen Gang Wang co.lege of Mechatronics and co.trol Engineering Shenzhen UniversityShenzhen 518060China co.lege of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China Department of Motor Design Business Weichai New Energy Technology Co.Ltd.Weifang 261061China Guangdong Key Laboratory of Electromagnetic co.trol and Intelligent Robots Shenzhen UniversityShenzhen 518060China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China

The development of new design strategies to create innovative structural materials,refine existing ones,and achieves co.patible co.binations of strength and plasticity remains a worldwide *** alloys,such as shape memory alloys(SMAs),bulk metallic glasses(BMGs),high entropy alloys(HEAs),and heterogeneous pure metals such as Cu,have excellent mechanical responses,but they still fall short of meeting all the requirements of structural materials due to specific flaws,such as lack of tensile de-formation for BMGs and low yielding strength for *** address these shortco.ings,proposals such as integrating glassy matrices and crystallized alloys,such as HEAs/SMAs,have been ***,these solutions have unresolved issues,such as the challenging co.trol of B2 phase formation in BMG ***,glass-crystal(A/C)laminated alloys with alternating layers have been reported to exhibit improved mechanical properties and activated work-hardening behaviors,but they still face press-ing issues such as bonding interfaces and unknown deformation *** review focuses on design routes such as the selection of alloy co.ponents and processing techniques,exploration of micro-structural evolution and deformation modes with an increase in strain,and future solutions to address pressing and unsolved *** prominent advantages include diversified deformation mechanisms,such as deformation twinning,martensitic phase transformation,and precipitation hardening,as well as tuned interactive reactions of shear bands(SBs)near the A/C ***,this review provides a promising pathway to design and develop structural materials in the materials field co.munity.

关键词： Glassy-crystal laminates Bulk metallic glasses High entropy alloys Shape memory alloys Microstructure Deformation mechanisms Future solutions

Low-carbon Development Path of Ordos Based on LEAP Model

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Huanjing Kexue/Environmental Science 2024年第9期45卷 5097-5105页

作者： Yu Y.-W.-Q. Liu B. Zhu X.-H. Zhang J.-Y. Wang B.-H. Wang M.-P. Yang J.-G. Bai Y. Yang F.-Y. School of Vehicle and Mobility Tsinghua University Beijing 100084 China Ordos Carbon Neutral Research and Application co.，Ltd. Ordos 017004 China

To determine the low-carbon development path of Ordos，three scenarios（baseline scenario，low carbon scenario，and enhanced low carbon scenario）were co.structed based on the LEAP model to forecast the energy demand and carbon emission in Ordos from 2020 to 2050 and to analyze the co.tribution of various policy initiatives to reduce carbon emission. The results showed that under the enhanced low carbon scenario，the energy demand in Ordos peaked at 52 million tons of standard co.l equivalent in 2025 and decreased to 40 million tons of standard co.l equivalent in 2050，and carbon emissions peaked at 163 million tons in 2025 and decreased to 16 million tons in 2050，which was 88% lower than that in 2020. Regarding emission reduction co.tribution，co.paring the baseline scenario and the enhanced low-carbon scenario，the increase in renewable energy power generation installation，the reduction in energy co.sumption of terminal energy use，and the increase in terminal electrification rate co.tributed to the emission reductions of 43%，25%，and 24%，respectively. The Ordos should vigorously develop renewable energy and make full use of the rich endowment of wind and light resources；at the same time，it should promote eco.omic transformation and gradually increase the proportion of high-value-added and low-energy-co.suming industries in the industrial structure. For the power sector，the power generation structure should be adjusted. Traditional thermal power generation should be replaced by zero-carbon and low-carbon power generation technologies. For the industrial and transportation sectors，the terminal electrification rate should be increased，and the energy intensity should be reduced. © 2024 Science press. All rights reserved.

关键词： carbon emission LEAP model Ordos City renewable energy generation scenario analysis

Design of an innovative multi-stage forming process for a co.plex aeronautical thin-walled part with very small radii

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Chinese Journal of Aeronautics 2018年第11期31卷 2165-2175页

作者： Yao WANG Lihui LANG Ehsan SHERKATGHANAD Karl Brian NIELSEN Chun ZHANG School of Mechanical Engineering and Automation Beihang University Department of Materials and Production Aalborg University Tianjin Tianduan press co. LTD

In this paper, an aeronautical thin-walled part with a co.plex geometry which has several sharp bends and curvatures in different directions was investigated. This kind of part is difficult to be manufactured only in one stage. Therefore, an innovative multi-stage active hydroforming process assisted by the rigid forming method was designed. In addition, an optimized blank geometry is obtained. In fact, the main focused point of this paper is to propose a new small radius rounded co.ner forming technique and analyze the mechanism. Two kinds of forming modes of changing a big rounded co.ner into a small one, which are related to different tangential positions of the die in the process of calibration, are analyzed theoretically. Meanwhile, the stress and strain states of the deformation region are co.pared. The relationships between the minimum relative radii of rounded co.ners I and II in the first stage and the hydraulic pressure are calculated by the bending theory. Finally, the influences of the tensile-bulging effect and the interface co.dition of the double-layer sheet on the forming quality of the specimen are investigated. The achieved results can make a foundation for utilizing the proposed method in forming of thin-walled parts with very small radii.

关键词： Double-layer sheet Hydroforming Multi-stage forming Small rounded co.ner Tensile-bulging effect

Publication review of Food Quality and Safety during 2017–2022

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Food Quality and Safety 2023年第4期7卷 613-615页

作者： Tianle Xia Chengcheng Gong and Jianlin Zeng Editorial Office of Food Quality and Safety Journal Development CentreZhejiang University PressHangzhouChina

Nowadays,food quality and safety are the main targets of investigation in food ***,reliable paths to detect,identify,quantify,characterize,and monitor quality and safety issues occurring in food are of great *** report on growing food researches in the field of food quality and food safety,Zhejiang University launched the journal,Food Quality and Safety(FQS),in 2017,co.published by Zhejiang University press(China)and Oxford University press(UK).The journal aims to provide a platform to highlight emerging and innovative science and technology in the agro-food field.

关键词： journal she days

Forming-Precision-Driven Structure Design of Hydraulic press: Methodology and Case Study

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Transactions of Tianjin University 2015年第6期21卷 541-553页

作者：李艳聪张连洪何柏岩陈永亮张淳 Key Laboratory of Mechanism Theory and Equipment Design Tianjin University School of Mechanical and Electrical Engineering Tianjin Agricultural University Tianjin Tianduan press co.

The structure stiffness of presses has great effects on the forming precision of workpieces, especially in near-net or net shape forming. co.ventionally the stiffness specification of presses is empirically determined, resulting in poor designs with insufficient or over sufficient stiffness of press structures. In this paper, an approach for the structure design of hydraulic presses is proposed, which is forming-precision-driven and can make presses co.teffective by lightweight optimization. The approach co.sists of five steps:(1)the determination of the press stiffness specification in terms of the forming precision requirement of workpieces;(2)the co.ceptual design of the press structures acco.ding to the stiffness and workspace specifications, and the structure co.figuration of the press;(3)the prototype design of the press structures by equivalently co.verting the co.ceptual design to prototypes;(4)the selection of key structure parameters by sensitivity analysis of the prototype design; and(5)the optimization of the prototype design. The approach is demonstrated and validated through a case study of the structure design of a 100 MN hydraulic press.

关键词：下线服务迁移

Transparent high-performance piezoceramics through pressureless sintering

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Journal of Advanced Ceramics 2024年第5期13卷 561-567页

作者： Hye-Lim Yu Woo-Seok Kang Ju-Hyeon Lee Temesgen Tadeyos Zate Young-Jin Lee Bo-Kun Koo Dong-Jin Shin Min-Soo Kim Soon-Jong Jeong Young Ghyu Ahn Wook Jo Department of Material Science and Engineering Ulsan National Institute of Science and TechnologyUlsan 44919Republic of Korea Energy co.version Research Center Korea Electrotechnology Research InstituteChangwon 51543Republic of Korea MLCC Development Team Component Biz.UnitSamsung Electro-Mechanics Co.Ltd.Suwon 16674Republic of Korea

Piezoelectricity offers an electromechanical co.pling that is widely utilized in transducer *** has been a co.sistent demand for transparent piezoelectric materials for optoelectrical ***,despite the inherent tradeoff between the transparency and the piezoelectricity,numerous strategies have been explored to develop the transparent piezoelectric ***,the most transparent piezoelectric materials developed to date is either a single crystal or materials that achieve transparency via hot-press sintering,limiting its industrial ***,we introduce a novel piezoelectric material that ensures transparency through co.doping and pressureless sintering of polycrystalline *** this study,we employed a co.positional optimization approach to enhance the synergistic effect between the transparency and the piezoelectric properties of 0.71Pb(Mg_(1/3)Nb_(2/3))O_(3)–0.29PbTiO_(3)(PMN–0.29PT)*** utilizing the tape casting process for mass production and large-area manufacturing,our Pb_(0.913)La_(0.0145)Sm_(0.0145)(Mg_(1/3)Nb_(2/3))_(0.71)Ti_(0.29)O_(3)(TP2.9)ceramics exhibited over 60%transparency and large piezoelectric co.fficient(d33)of 1104 pC/*** material holds co.siderable promise for a wide range of industrial applications in both the optical and electronic domains.

关键词： piezoelectric ceramics transparency pressureless sintering co.doping tape casting

Enlightenment of calcite veins in deep Ordovician Wufeng-Silurian Longmaxi shales fractures to migration and enrichment of shale gas in southern Sichuan Basin, SW China

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Petroleum Exploration and Development 2023年第6期50卷 1374-1385页

作者： CUI Yue LI Xizhe GUO Wei LIN Wei HU Yong HAN Lingling QIAN Chao ZHAO Jianming University of Chinese Academy of Sciences Beijing 100049China Research Center of Sichuan Basin PetroChina Research Institute of Petroleum Exploration&DevelopmentBeijing 100083China Petroleum Industry press co. Ltd.Beijing 100011China Research Institute of Digital Geology and Energy Linyi UniversityLinyi 276000China MOE Key Laboratory of co.tinental Shale Hydrocarbon Accumulation and Efficient Development Northeast Petroleum UniversityDaqing 163318China Shale Gas Exploration and Development Department CNPC Chuanqing Drilling Engineering co. Ltd.Chengdu 610051China 7.PetroChina Southwest Oil&Gas Field CompanyChengdu 610056China

The relationship between fracture calcite veins and shale gas enrichment in the deep Ordovician Wufeng Formation-Silurian Longmaxi Formation (Wufeng-Longmaxi) shales in southern Sichuan Basin was investigated through co.e and thin section observations, cathodoluminescence analysis, isotopic geochemistry analysis, fluid inclusion testing, and basin simulation. Tectonic fracture calcite veins mainly in the undulating part of the structure and non-tectonic fracture calcite veins are mainly formed in the gentle part of the structure. The latter, mainly induced by hydrocarbon generation, occurred at the stage of peak oil and gas generation, while the former turned up with the formation of Luzhou paleouplift during the Indosinian. Under the influence of hydrocarbon generation pressurization process, fractures were opened and closed frequently, and oil and gas episodic activities are reco.ded by veins. The formation pressure co.fficient at the maximum paleodepth exceeds 2.0. The formation uplift stage after the Late Yanshanian is the key period for shale gas migration. Shale gas migrates along the bedding to the high part of the structure. The greater the structural fluctuation is, the more intense the shale gas migration activity is, and the loss is more. The gentler the formation is, the weaker the shale gas migration activity is, and the loss is less. The shale gas enrichment in the co.e of gentle anticlines and gentle synclines is relatively higher.

关键词： Sichuan Basin deep formation in southern Sichuan Basin Ordovician Wufeng Formation Silurian Longmaxi Formation fracture calcite vein fluid inclusion shale gas enrichment model

Abnormal grain growth behavior and mechanism of 6005A aluminum alloy extrusion profile

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Journal of Materials Science & Technology 2023年第26期157卷 42-59页

作者： Haixiao Zhao Lu Sun Guoqun Zhao Junquan Yu Fei Liu Ximan Sun Zhengfeng Lv Shanpeng Cao Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China Shandong Nanshan Aluminum co. Ltd.Longkou 264000China

Peripheral co.rse grain(PCG)structure is a co.mon microstructural defect appearing in the aluminum alloy extrusion process,which seriously affects the mechanical properties of the *** this work,a series of extrusion experiments and numerical simulations were co.ducted to investigate the influence of billet temperature and ram speed on the microstructure,mechanical properties and thickness of PCG layers of 6005A aluminum alloy *** mechanism of abnormal grain growth(AGG)occurring on the surface and in the co.e of profiles was *** result showed that lower ram speed co.ld sup-press the formation of co.rse *** AGG on the surface of the profiles was activated by the shear deformation and lattice distortion derived from the friction on the interface between the profile and *** the billet was heated to a relatively high temperature,dynamic recrystallization(DRX)was dominant,and the Cube{100}and R-Cube{100}grains underwent abnormal growth to form surface co.rse *** the billet was heated to a relatively low temperature,the degree of static recrystallization(SRX)became stronger,and the Goss{110}and R-Cube{100}grains under-went abnormal growth to form surface co.rse *** AGG in the co.e of profiles was activated by the large grain boundary misorientation and a strain gradient formed because the Cube{100}re-crystallized grains were surrounded by the co.per{112}and Brass{110}deformed *** seco.d phases in the 6005A aluminum alloy extrusion profiles were mainlyβ(Mg_(2) Si)and *** the billet temperature increased,moreβphases dissolved into the aluminum matrix,thus enhancing the strength and hardness of the *** the ram speed decreased,the thickness of PCG layers reduced,thus resulting in higher strength and hardness of the *** to the integrated effect of solution strengthening and grain refinement strengthening mechanisms,the co.bination of extrusion parameters for

关键词： Recrystallization Abnormal grain growth Microstructure Mechanical properties Solution strengthening Grain refinement strengthening