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61.
Bai-song Liu ) Guo-sen Zhu ) Huan-xi Li ) Ben-hai Li ) Yang cui ) Ai-min Cui ) ) School of Material Science Engineering Beihang University Beijing China ) Shougang Research Institute of Technology Beijing China ) Qian'an Iron Steel Company Qian'an China 《北京科技大学学报(英文版)》2010,17(1):22-27
The decarburization behaviors of ultra low carbon steel in a 210-t RH vacuum degasser were investigated under practical operating conditions.According to the apparent decarburization rate constant (KC) calculated by the carbon content in the samples taken from the hot melt in a ladle at an interval of 1-2 min,it is observed that the total decarburization reaction period in RH can be divided into the quick decarburization period and the stagnant decarburization period,which is quite different from the tradit... 相似文献
62.
Particle simulation of the failure process of brittle rock under triaxial compression 总被引:1,自引:0,他引:1
Ming Xia ) Ke-ping Zhou) ) School of Resources Safety Engineering Central South University Changsha China ) Ma’anshan Institute of Mining Research Ma’anshan China 《北京科技大学学报(英文版)》2010,17(5):507-513
In order to investigate the failure process of brittle rock under triaxial compression through both experimental and numerical approaches, the particle simulation method was used in numerical simulations and the simulated results were compared with those of the experiment. The numerical simulation results, such as fracture propagation, microcrack distribution, stress-strain response, and damage patterns, were discussed in detail. The simulated results under various confining pressures (0-60 MPa) are in good... 相似文献
63.
Effects of welding wire composition and welding process on the weld metal toughness of submerged arc welded pipeline steel 总被引:2,自引:0,他引:2
De-liang Ren ) Fu-ren Xiao) Peng Tian) Xu Wang) Bo Liao) ) Key Lab of Metastable Materials Science & Technology College of Materials Science & Engineering Yanshan University Qinhuangdao China ) Department of Materials Science Engineering Shijiazhuang Railway Institute Shijiazhuang China ) Steel Pipe Works of North China Petroleum Qing County China 《北京科技大学学报(英文版)》2009,16(1):65-70
The effects of alloying elements in welding wires and submerged arc welding process on the microstructures and low-temperature impact toughness of weld metals have been investigated.The results indicate that the optimal contents of alloying elements in welding wires can improve the low-temperature impact toughness of weld metals because the proentectoid ferrite and bainite formations can be suppressed,and the fraction of acicular ferrite increases.However,the contents of alloying elements need to vary along with the welding heat input.With the increase in welding heat input,the contents of alloying elements in welding wires need to be increased accordingly.The microstructures mainly consisting of acicular ferrite can be obtained in weld metals after four-wire submerged arc welding using the wires with a low carbon content and appropriate contents of Mn,Mo,Ti-B,Cu,Ni,and RE,resulting in the high low-temperature impact toughness of weld metals. 相似文献
64.
Zhuo-ying Tan ) Si-jing Wang ) Mei-feng Cai ) ) State Key Laboratory of High-Efficient Mining Safety of Metal Mines Ministry of Education of China Beijing China ) School of Civil Environmental Engineering University of Science Technology Beijing China ) Institute of Geology Geophysics Chinese Academy of Sciences Beijing China ) School of Civil Engineering Tsinghua University Beijing China 《北京科技大学学报(英文版)》2009,16(2):135-142
An instrumented drilling system can be applied for the acquisition of drilling process parameters.The system can provide continuous and huge data for geotechnical engineering.However, due to the complexity of ground strata, the variation in the drilling parameters with stratigraphical characteristics is great and the correlation between likely comparable parameters is not high, which limits the use of conventional correlation approaches in this field.How to use the data for engineering and how to get a reasonable interpretation for the relationships among the drilling parameters, as well as between a drilling parameter and formational character-istics, become a technical choke point for the development and application of the instrumented drilling system.Based on similarity criteria, the extraction of sample data and characteristics, the pretreatment of data and feature matching algorithms have been ana-lyzed and an approach of slope coefficient searching identification has been established.A case study was carried out for the similar-ity between the rotational speed of the drill bit, flushing pressure, and effective thrust force graphics in general weathered granite.The result shows that the similarity coefficients between the rotational speed of the drill bit, flushing pressure, and effective thrust force are 0.72 and 0.83, respectively.Although there are differences between the distances of the graphics, the curves of both rota- tional speed and flushing pressure agree with the effective thrust curve in shape, which provides a possible method for the identifica- tion of various formations by use of the similarity between feature drilling parameters. 相似文献
65.
Mechanical performance and texture characteristic of an IF steel containing Nb and Ti by double cold rolling 总被引:1,自引:0,他引:1
Ling-yun Wang) Peng Zhang ) Wei Li) Guang-jie Huang) ) College of Materials Science Engineering Chongqing University Chongqing China ) Technology Institute of Sichuan Chuanwei Group Co. Ltd. Weiyuan China 《北京科技大学学报(英文版)》2009,16(1):51-57
Single cold rolling and double cold rolling were applied to hot rolled strips with different reduction ratios. The evolutions of {100},{111} and Goss face texture during double rolling were investigated by comparing the orientation distribution function(ODF) of the double rolled sample with that of the single rolled one. The double cold rolling texture is characterized by a higher γ-texture and a lower α-texture,and the {111}<112> component is improved remarkably. Based on the TEM observation and mechanical... 相似文献
66.
Guo-jun Wang ) Bai-qing Xiong) Yong-an Zhang) Zhi-hui Li) Pei-yue Li) ) State Key Laboratory for Fabrication Processing of Nonferrous Metals General Research Institute for Nonferrous Metals Beijing China ) Northeast Light Alloy Co. Ltd. Harbin China 《北京科技大学学报(英文版)》2009,16(4):427-431
The microstructure of the as-cast 2D70 aluminum alloy and its evolution during homogenization were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analysis. The results indicate that the microstructure of the as-cast 2D70 aluminum alloy mainly consists of the dendritic network of aluminum solid solution and intermetallic compounds (Al2CuMg, Al2Cu, Al9FeNi, Cu2FeAl7... 相似文献
67.
Evolution of carbides and carbon content in matrix of an ultra-high carbon sintered steel during heat treatment process 总被引:2,自引:0,他引:2
Yuan-zhi Zhu ) Zhe Zhu) Zhi-min Yin) Zhi-dong Xiang) ) Key Laboratory of the Ministry of Education of China for Ferrous Metallurgy Resources Utilization Wuhan University of Science Technology Wuhan China ) School of Materials Metallurgy China ) School of Material Science & Engineering Central South University Changsha China 《北京科技大学学报(英文版)》2009,16(3):299-303
DTA, thermal expansion, XRD, and SEM were used to evaluate the effect of quenching temperature on the mechanical properties and microstructure of a novel sintered steel Fe-6Co-1Ni-5Cr-5Mo-1C. Lattice parameters and the mass fraction of carbon dissolved in the matrix of the steel quenched were investigated. It is discovered that the hardness of the steel increases with quench-ing temperature in the range of 840-900℃ and remains constant in the range of 900 to 1100℃. It decreases rapidly when the tem-perature is higher than 1100℃. The mass fraction of carbon dissolved in the matrix of the steel quenched at 840℃ is 0.38, but when the quenching temperature is increased to 1150℃, it increases to 0.98. The carbides formed during sintering are still present at grain boundaries and in the matrix of the steel quenched at low quenching temperatures, such as 840℃. When the quenching temperature is increased to 1150℃, most of the carbides at grain boundaries are dissolved with just a small amount of spherical M23C6 existing in the matrix of the quenched steel. 相似文献
68.
Ji-ping Chen) Yong-lin Kang ) Ying-min Hao) Guang-ming Liu) Ai-ming Xiong) ) School of Materials Science Engineering University of Science Technology Beijing Beijing China ) The State Key Laboratory for Advanced Metals Materials China ) Steel Research Institute of Shougang Beijing China 《北京科技大学学报(英文版)》2009,16(5):540-548
A Ti+Nb bearing ultra-low carbon bake hardening sheet steel hot-rolled in the conventional austenite region and in the ferrite region with lubrication was experimentally studied.Subsequent cold rolling and continuous annealing processes were also conducted.The results show that microstructures of ultra-low carbon bake hardening hot strips at room temperature are basically irregular polygonal ferrites.The yield strength,ultimate tensile strength,n value,and r value of the No.2 specimen hot-rolled in the ferr... 相似文献
69.
Research on indoor experimentation of range SAL imaging system 总被引:1,自引:0,他引:1
GUO Liang XING MengDao ZHANG Long TANG Yu & BAO Zheng State Key Laboratory of Radar Signal Processing Xidian University Xi’an China Xi’an Polytechnic University Xi’an 《中国科学E辑(英文版)》2009,52(10):3098-3104
By means of advantages of both SAR and lidar, the combination of the techniques of (inverse) synthetic aperture and lidar makes it possible to obtain high resolution 2-D image. In this paper, an indoor experimental system of inverse synthetic aperture lidar imaging is given and a processing approach is presented. The given system is in the mode of lidar system with separated receiver and transmitter, which can effectively eliminate the jamming from the lens or/and the intersection between two optic fibers. ... 相似文献
70.
光伏发电功率预测对提高光伏电站控制、调度性能以及保证电网的安全稳定运行具有重要意义。提出一种基于相似日和回声状态网络(ESN)的光伏发电功率预测模型。首先运用相关性分析法对光伏发电功率的影响因素进行了深入分析,并筛选出其主要影响因素;再利用主要影响因素的历史气象信息建立气象特征向量,通过计算灰色关联度(GRA)寻找合适的相似日;最后运用ESN创建预测模型,利用相似日历史数据训练ESN,而后对预测日的输出功率进行逐时预测。算例表明,对比传统模型,GRA-ESN模型具有更高的预测精度和更好的可行性。 相似文献