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Carbides precipitation and their evolution of Cr15Co10Mo5-alloyed heat-resistant bearing steel after tempering at different temperatures

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Journal of Iron and Steel Research International 2019年第10期26卷 1096-1105页

作者： mao-guo Xiao Xin-yang Lü Dong-hui Li Shao-hong Li Kun-yu Zhao mao-sheng yang School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing 100081China

The carbides precipitation and their evolution at elevated tempering temperature in Crl5Col0Mo5-alloyed heat-resistant bearing steel were investigated by means of the transmission electron *** results show that there is no carbide precipitated from the martensitic matrix when the sample was tempered at 480℃.However,when the sample was tempered at 540℃,a large number of stable spherical M6C carbides precipitated in the test ***,there are three types of carbides precipitated from the matrix including M6C,M2C and M23C6 carbides when the tempering temperature reached 600℃.The mechanical properties also present a correlation with the evolution of carbides during tempering at different *** indicates that the strengthening mechanism of the steel is mainly attributed to the precipitation of carbides and their evolution,including the morphologies and types of carbides at different *** addition,the austenitic layers with a thickness of about 30 nm have been obtained between the martensite laths after tempering at 600℃.The austenitic layers will produce transformation-induced plasticity effects to improve the toughness of the steel.

关键词： High-temperature bearing steel Carbide evolution Phase diagram Diffusion coefficient Secondary hardening Austenitic layer

Wear Behavior and Mechanism of a Sliding Pair of 0.1C-3Cr-2W-V Nitrided Steel Rubbing against an Aluminum Bronze Alloy

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Journal of Iron and Steel Research International 2016年第3期23卷 281-288页

作者： Guang-hong WANG sheng-guan QU Zhi-hua XIONG Fu-qiang LAI Xiao-qiang LI mao-sheng yang School of Mechanical and Automotive Engineering South China University of Technology Institute of Special Steel Central Iron and Steel Research Institute

Wear behavior and mechanism of plasma nitrided steel oscillating against a heat-treated and an untreated aluminum bronze alloy were investigated using an Optimol SRV *** influence of heat treatment on the mechanical properties of the alloy was ***,the wear debris was also examined to understand the wear *** results show that a 220-230μm nitrided layer,which was harder than the substrate,was obtained on the steel *** tensile strength and hardness of the alloy are found to be significantly improved by the heat treatment associated with low impact *** heat treatment of the alloy did not obviously decrease the friction coefficient of the nitrided steel-bronze ***,the wear loss of the nitrided steel increased when it mated with the treated bronze by a severe three-body *** nitrided steel was mainly damaged by fatigue *** plane contact conditions,the wear debris was mainly generated from the bronze part and can escape from the interface before being oxidized,leading to the phase structure of all the debris being copper rather than copper oxides.

关键词： steel plasma nitriding aluminum bronze sliding wear three-body abrasion

Effects of traditional heat treatment and a novel deep cryogenic treatment on microstructure and mechanical properties of low-carbon high-alloy martensitic bearing steel

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Journal of Iron and Steel Research International 2021年第3期28卷 370-382页

作者： Dong-hui Li Wen-chao He Xu Zhang mao-guo Xiao Shao-hong Li Kun-yu Zhao mao-sheng yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093YunnanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing100081China

The effects of traditional heat treatment(quenching and then tempering)and deep cryogenic treatment on the microstructure and mechanical properties of a low-carbon high-alloy martensitic bearing steel were studied by Rockwell hardness test,X-ray diffractometry,scanning electron microscopy and transmission electron *** results show that the deep cryogenic treatment promotes the transformation of the retained austenite to martensite during cooling,which leads to the hardness of the sample after deep cryogenic treatment higher than that at the quenched ***,the carbon content in the martensite matrix after different treatments was calculated and the results indicated that deep cryogenic treatment can promote the segregation of carbon atoms in martensite to *** segregated carbon atoms act as and grow into nuclei for the formation of fine carbide particles during subsequent *** this resulted in the fact that the hardness of the tempered experimental steel after deep cryogenic treatment is higher than that without deep cryogenic treatment.

关键词： Heat treatment High-alloy martensitic bearing steel Deep cryogenic treatment Carbide Retained austenite

Effect of deep cryogenic treatment on martensitic lath refinement and nano-twins formation of low carbon bearing steel

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Journal of Iron and Steel Research International 2020年第1期27卷 105-113页

作者： Xin-yang Lü Zhi-wei Wu Xiao He Jun Li Shao-hong Li mao-sheng yang Kun-yu Zhao Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing 100081China

The effect of heat treatment and deep cryogenic treatment on microstructural evolution of low carbon martensitic bearing steel was *** experimental results showed that the lath martensite was obtained by quenching and a few twins as substructures formed in some martensitic *** rudiment of sub-interfaces of martensitic lath was formed in the highdensity dislocation regions after deep cryogenic treatment;meanwhile,the number of twins increased,especially in the highdensity dislocation *** phenomenon is due to the increase in internal stress caused by cryogenic *** tempering,the rudiment of sub-interface further evolved into the martensitic lath boundary,and thus the original martensitic laths were *** twins formed by cryogenic treatment did not disappear after *** addition,small quantities of annealing twins formed in tempering *** laths morphology and substructures in different stages of the heat and deep cryogenic treatment were observed by tninsmission electron microscopy.

关键词： Low carbon bearing steel-Deep cryogenic treatment Internal stress Sub-interface Nano-twin

The influences of perforating phase and bedding planes on the fracture deflection in laminated shale

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Petroleum Science 2024年第2期21卷 1221-1230页

作者： Ming-Zhe Gu mao sheng Xiao-Ying Zhuang Xin-Yi Li Gen-sheng Li National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China College of Petroleum Engineering China University of PetroleumBeijing102249China College of Civil Engineering Tongji UniversityShanghai200092China

The perforating phase leads to complex and diverse hydraulic fracture propagation behaviors in laminated shale formations. In this paper, a 2D high-speed imaging scheme which can capture the interaction between perforating phase and natural shale bedding planes was proposed. The phase field method was used to simulate the same conditions as in the experiment for verification and hydraulic fracture propagation mechanism under the competition of perforating phase and bedding planes was *** results indicate that the bedding planes appear to be no influence on fracture propagation while the perforating phase is perpendicular to the bedding planes, and the fracture propagates along the perforating phase without deflection. When the perforating phase algins with the bedding planes, the fracture initiation pressure reserves the lowest value, and no deflection occurs during fracture propagation. When the perforating phase is the angle 45°, 60°and 75°of bedding planes, the bedding planes begin to play a key role on the fracture deflection. The maximum deflection degree is reached at the perforating phase of75°. Numerical simulation provides evidence that the existence of shale bedding planes is not exactly equivalent to anisotropy for fracture propagation and the difference of mechanical properties between different shale layers is the fundamental reason for fracture deflection. The findings help to understand the intrinsic characteristics of shale and provide a theoretical basis for the optimization design of field perforation parameters.

关键词： Shale Propagation Perforating Bedding Structure

Influences of shale microstructure on mechanical properties and bedding fractures distribution

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Petroleum Science 2024年第3期21卷 1944-1954页

作者： Ming-Zhe Gu mao sheng Shi-Zhong Cheng Fan-Hao Gong Gen-sheng Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing2249China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Shenyang Center of China Geological Survey ShenyangLiaoning110034China

The difference in microstructure leads to the diversity of shale mechanical properties and bedding fractures distribution *** this paper,the microstructure and mechanical properties of Longmaxi marine shale and Qingshankou continental shale were studied by X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)with mineral analysis system,and ***,the typical bedding layers area was properly stratified using Focused Ion Beam(FIB),and the effects of microstructure and mechanical properties on the distribution patterns of bedding fractures were *** results show that the Longmaxi marine shale sample contains more clay mineral grains,while the Qingshankou continental shale sample contains more hard brittle mineral grains such as *** Longmaxi marine shale sample,hard brittle minerals with grain sizes larger than 20μm is18.24%and those with grain sizes smaller than 20μm is 16.22%.For Qingshankou continental shale sample,hard brittle minerals with grain sizes larger than 20μm is 40.7%and those with grain sizes smaller than 20μm is 11.82%.In comparison to the Qingshankou continental shale sample,the Longmaxi marine shale sample has a lower modulus,hardness,and *** shales are formed by alternating coarse-grained and fine-grained layers during *** average single-layer thickness of Longmaxi marine shale sample is greater than Qingshankou continental shale *** two types of shale have similar bedding fractures distribution patterns and fractures tend to occur in the transition zone from coarse-grained to fine-grained *** orientation of the fracture is usually parallel to the bedding plane and detour occurs in the presence of hard brittle *** fracture distribution density of the Longmaxi marine shale sample is lower than that of the Qingshankou continental shale sample due to the strong heterogeneity of the Qingshankou continental *** current resea

关键词： Shale Nanoindentation Microstructure Mechanical property Fracture

A framework of force of information influence and application for C4KISR system

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Journal of Systems Engineering and Electronics 2024年第2期35卷 430-443页

作者： mao Shaojie DIAO Lianwang SUN Yu WANG Heng YI Kan XU Xin mao Xiaobin ZHANG Kecheng sheng Long Science and Technology on Information Systems Engineering Laboratory The 28th Research Institute of China Electronics Technology Group CorporationNanjing 210007China Unit 94860 of the PLA Nanjing 210008China

The subversive nature of information war lies not only in the information itself, but also in the circulation and application of information. It has always been a challenge to quantitatively analyze the function and effect of information flow through command, control, communications, computer, kill, intelligence,surveillance, reconnaissance (C4KISR) system. In this work, we propose a framework of force of information influence and the methods for calculating the force of information influence between C4KISR nodes of sensing, intelligence processing,decision making and fire attack. Specifically, the basic concept of force of information influence between nodes in C4KISR system is formally proposed and its mathematical definition is provided. Then, based on the information entropy theory, the model of force of information influence between C4KISR system nodes is constructed. Finally, the simulation experiments have been performed under an air defense and attack scenario. The experimental results show that, with the proposed force of information influence framework, we can effectively evaluate the contribution of information circulation through different C4KISR system nodes to the corresponding tasks. Our framework of force of information influence can also serve as an effective tool for the design and dynamic reconfiguration of C4KISR system architecture.

关键词： information warfare command control communications computer kill intelligence surveillance reconnaissance(C4KISR)system information circulation force of information influence information entropy

The cluster digging behavior of larvae confers trophic benefits to fitness in insects

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Insect Science 2024年第3期31卷 870-884页

作者： Yujie Wu Qiang Wang Weikang yang sheng Zhang Chuan-Xi mao Nana He Shaojie Zhou Chuanming Zhou Wei Liu School of Plant Protection Anhui Agricultural UniversityAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Province Engineering Laboratory for Green Pesticide Development and ApplicationHefeiChina College of Plant Protection Nanjing Agricultural UniversityNanjingChina School of Teacher Education Nanjng Xiaozhuang UniversityNanjingChina State Key Laboratory of Biocatalysis and Enzyme Engineering Hubei Province Key Laboratory of Biotechnology of Chinese Traditional MedicineNational&Local Joint Engineering Research Center of High-throughput Drug Screening TechnologySchool of Life ScienceHubei UniversityWuhanChina

Collective behaviors efficiently impart benefits to a diversity of species ranging from bacteria to *** larvae tend to cluster and form coordinated digging groups under crowded conditions,yet understanding the rules governing this behavior is in its *** primarily took advantage of the Drosophila model to investigate cooperative foraging ***,we report that Drosophila-related species and the black soldier fly have evolved a conserved strategy of cluster digging in food ***,we investigated relative factors,including larval stage,population density,and food stiffness and quality,that affect the cluster digging ***,oxygen supply through the posterior breathing spiracles is necessary for the organization of digging *** importantly,we theoretically devise a mathematical model to accurately calculate how the cluster digging behavior expands food resources by diving depth,cross-section area,and food *** found that cluster digging behavior approximately increases 2.2 fold depth,1.7-fold cross-section area,and 1.9 fold volume than control groups,*** of food sources significantly facilitates survival,larval development,and reproductive success of Drosophila challenged with competition for limited food resources,thereby conferring trophic benefits to fitness in ***,our findings highlight that the cluster digging behavior is a pivotal behavior for their adaptation to food scarcity,advancing a better understanding of how this cooperative behavior confers fitness benefits in the animal kingdom.

关键词： cluster digging determinant development fecundity larvae mathematical model

Metal-free Optical Pressure Sensor with High Sensitivity and Extensive Range

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1291-1300页

作者： mao Ji Meng Huang Haomin Lyu sheng Shi Bo Qi Chengrong Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China IEEE CSEE

Pressure monitoring of a transformer oil tank can grasp the pressure change process caused by gas production when severe internal defects occur and take timely measures to ensure the safe operation of the *** pressure sensors generally use metal encapsulation or have an air cavity structure,threatening the transformer’s insulation if it is directly used inside the *** this end,this paper proposes a method for developing a high-sensitivity,large-range,and metallizationfree optical pressure sensing device with temperature *** grating is encapsulated by fluorosilicone rubber and supplemented by an epoxy resin shielding shell on the *** the same time,a double-grating vertical arrangement is adopted to improve pressure measurement sensitivity,further avoiding the influence of temperature rise caused by a defect of the transformer on the measurement result of the *** addition,by optimizing the geometric structure of the internal sensitizing element,pre-stretching length of the fiber grating,gap distance,and other parameters,probe size can be reduced while ensuring the sensor’s *** show the proposed method can meet the requirements of sensor fabrication with different sensitivities and ranges,and to a certain extent,both high sensitivity and extensive ranges can be taken into *** sensitivity of the fabricated prototype is 15 pm/kPa,and the range is about 0.2 *** the same time,the metal-free feature of the sensor makes it suitable for use in various oil-immersed power *** records oil pressure changes caused by oil discharge breakdown,making it sensitive to small pressure changes in early failures.

关键词： Highly sensitive extensive range optical sensing no metallization pressure perception temperature compensation transformer