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Modeling and Optimizing of Deformed Steel Bars Hot Rolling

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International Journal of Minerals,Metallurgy and materials 1999年第4期13卷 289-291页

作者： Peng Zhang Yunhui Du Xueping Ren(material science and engineering school, university’ of science and technology’ Beijing, Beijing 100083) material science and engineering school University of Science and Technology Beijing Beijing 100083 China

Based on experimental data, a nonlinear model about tensile strength and technical parameters such as Mn and St content, finishing rolling speed and finishing rolling temperature for deformed steel bars in the process of hot rolling was established by using artificial neural networks. The model can be optimized with a genetic algorithm. The optimum rolling parameters were obtained.

关键词： artificial neural networks modeling genetic algorithm, optimizing

Corrosion Fatigue Behavior of Duplex Stainless Steel in 3.5% Sodium Chloride Solution

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Journal of university of science and technology Beijing 2001年第2期8卷 133-136页

作者： S. H Abubakir, Yinshun Wu, Baofeng Ding, Jiuqing Li Bei Cao (material science and engineering school, university of science and technology Beijing, Beijing 100083, China) material Sci. and engineering school University of Science and Technology Beijing 100083 China

The corrosion fatigue behavior of duplex stainless steel (DSS) was studied at different cyclic stress levels in 3.5%NaCl (mass fraction, so as the follows) solution (pH=7) at 50 degreesC. The results showed that DSS was susceptible to pitting corrosion and corrosion fatigue. Both intergranluar corrosion cracking and transgranlular corrosion cracking initiated at the bottom of pitting holes. Furthermore, the corrosion fatigue properties of DSS in 3.5%NaCl solution may be relatived to complex electrochemical and mechanical coupling effects between the three phases (austenite, ferrite and martensite), where martensite and ferrite were anodic in the corrosion cell and could be prone to cracking under certain condition.

关键词： corrosion fatigue duplex stainless steel sodium chloride solution

The characteristics of arc beam shaping in hybrid plasma and laser deposition manufacturing

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science China(Technological sciences) 2006年第2期49卷 238-247页

作者： ZHANG Hai’ou1, QIAN Yingping1,3, WANG Guilan1 & ZHENG Qiguang2 1. school of material science and technology, Huazhong university of science and technology, Wuhan 430074, China 2. Institute of Laser technology and engineering, Huazhong university of science and technology, Wuhan 430074, China 3. Mechanical engineering College, Hubei university of technology, Wuhan 430068, China school of material science and technology Huazhong University of Science and Technology Wuhan China Mechanical engineering College Hubei University of Technology Wuhan China Institute of Laser technology and engineering Huazhong University of Science and Technology Wuhan China

As a new direct metal prototyping technology,the hybrid plasma and laser deposition manufacturing (PLDM) is proposed in this paper. In order to figure out the characteristics of plasma arc beam and mould in the PLDM process of high temperature alloy, the high speed CCD camera is used to obtain the picture around the plasma arc. Afterwards the sketch of picture is clearly obtained. And the effect of laser parameter, such as average power, pulse width, pulse repetition frequency and the angle between laser beam and plasma arc beam on the plasma arc appearance, is studied experimentally. The results show that the modality of plasma arc beam is markedly influenced by laser beam. And the improvements of shape precision and surface state of the layer deposited by PLDM are confirmed.

关键词： plasma hybrid laser, direct deposition, plasma arc beam, molding character, high-temperature alloy.

GTA Welds of Iron-Aluminide Based Alloys

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Journal of university of science and technology Beijing 2001年第1期8卷 39-42页

作者： Dechun Gao, Wangyue Yang, Min Dong, Jihua Huang, Yuanding Huang, Zuqing Sun material science and engineering school, university of science and technology Beijing, Beijing 100083, China material Sci. and engineering school Univ. of Sci. and Technology Beijing Beijing 100083 China

The weldability of two Fe3Al-based intermetallic alloys and one Fe-16%Al-based (atom fraction) alloy has been investigated for gas tungsten are (GTA) welding on sheets with a thickness of 2 mm. The results indicated that pre-heating and post-annealing treatment were important procedures for retarding cold crack initiation and the propel selection of filler could effectively improve the weldability. For the same alloys with the same welding filler, it is better to choose lower welding current, in another word, lower heat input.

关键词： iron-aluminide gas tungsten arc welding weldability filler

Preparation of semi-solid AlSi7Mg alloy slurry with big capability

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Rare Metals 2010年第6期29卷 642-645页

作者： LI Sha and MAO Weimin school of materials science and engineering,university of science and technology Beijing,Beijing 100083,China school of materials science and engineering University of Science and Technology Beijing Beijing China

Semi-solid AlSi7Mg alloy slurry was prepared by low superheat pouring and weak traveling-wave electromagnetic *** effects of pouring temperature and stirring power on the microstructure of AlSi7Mg alloy slurry were *** results show that the semi-solid AlSi7Mg alloy slurry of 5 kg can be *** new technology can save energy and make the pouring process *** the pouring temperature is decreased at a stirring power of 0.41 kW,the shape of primary α-Al grains gradually changes from dendritic-like to *** the alloy melt is poured at the temperature（630°C） with a certain superheat,the pouring process becomes easier,and the spherical microstructure of AlSi7Mg alloy slurry can be prepared by the weak traveling-wave electromagnetic *** the pouring temperature is 630°C,increasing the stirring power appropriately can result in better spherical primary α-Al grains,but if the stirring power is increased to a certain value（1.72 kW）,the shape of primary α-Al grains does not obviously improve when the stirring power is continually increased.

关键词： aluminum alloys metal forming semisolid slurry electromagnetic stirring microstructure

A New Safety Electric Initiating System

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International Journal of Minerals,Metallurgy and materials 1999年第4期13卷 306-308页

作者： Daze Lin(Resource engineering school, university of science and technology Beijing, Beijing 100083, China) Univ of science and technology Beijing Beijing China

Based on the analysis of weakness on the safety of traditional electric detonators, a BJ-l safety electric detonator initiatingsystem and its corresponding safe examination technique were successfully developed. By leading false foot wires and taking advantageof the transmitting frequency band of Mo-Zn ferrite, detonators in this new system can completely impede the direct induction of outsidecrosstalk that may cause casual firing in the ordinary as well as eleclromagnetic ones. Possible causality by lightning was discussed. Results are presented, of its safety tests on resistance to direct and alternating current, electrostatic, and crosstalk induced by damp leakagein saturated salty water.

关键词： electric detonator blasting engineering, electric initiating system, safety

Producing Calcium-Bearing Mullite Thermal-Insulating Refractories by Kyanite

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International Journal of Minerals,Metallurgy and materials 1999年第1期13卷 50-53页

作者： Wen Ni (Resources engineering school, university of science and technology Beijing, Beijing 100083, China) Resources engineering school University of Science and Technology Beijing Beijing 100083 China

To improve the physical properties, a series of experiments have been camed out to produce calcium-bearing mullite thermal-insulating refractories by using kyanite as major raw materials. The experiments were carried out by a foaming technique and using white cement as a combing agent. The results show that the calcium-bearing mullite refractory has much better physical properhes than traditional clay refractory and high-alumina refractory.

关键词： mullite thermal-insulating refractory kyanite

Mechanical Properties and Erosive Wear Resistance of Zirconia Toughened Al_2O_3-TiC Ceramics

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International Journal of Minerals,Metallurgy and materials 2000年第2期14卷 110-114页

作者： Lihua Xu Fang Lian Yuyan Guo Qiang Zhen Jose Maria Fonte Ferreira Fuming Wang Wenchao Li(material science and engineering school, university of science and technology Beijing, Beijing 100083, China)(Metallurgy school, university of science and Tech material science and engineering school University of Science and Technology Beijing Beijing 100083 China Metallurgy school University of Science and Technology Beijing Beijing 100083 China Department of Ceramic and Glass engineering University of Aveiro 3810-193 Aveiro Portugal

The effect of ZrO2, content on the fracture toughness, flexural strength and Vickers hardness as well as the erosive wear resistan properties of zirconia toughened Al2O3-TiC ceramic composites has been investigated. The results showed that the improvement in fracture toughness and flexure strength of composites with the content of zirconia less than 50% and 10% in mass fraction respectively,is primarily attributed to stress-induced transformation toughening by the analyse of X-ray diffraction. The dependance of erosion wear resistance on the attak angle and the content of ZrO2, panicles of the composites was also revealed. It is found that the erosion rate of the composites has a sharp rise at a attack angle over 65°. This phenomenon is due to a brittle response to the erosion test by microsmictural observation on eroded surface.

关键词： mechanical properties, erosion ceramic composites

EXPERIMENTAL STUDY ON TRIBOLOGICAL PROPERTIES OF FULLERENE COPOLYMER NANOBALL

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Chinese Journal of Mechanical engineering 2000年第3期13卷 201-205页

作者： Lei Hong (school of Mechanical science and engineering, Huazhong university of science and technology) Guan Wenchao, Liao Daoxun (Huazhong university of science and technology) 华中科技大学湖北武汉

A novel fullerene-styrene-maleic anhydride copolymer is reported. TEM analyses shows it is water- soluble nanoball of average diameter of about 83 nm. The tribological behavior is evaluated by foul-ball machine. It was found that addition of fullerene copolymer to base stock (2%triethanolamine aqueous solution)resulted in a raise in load-carrying ability(F value)from 130 N to maximum 480 N, and a reduction in coefficient of friction from 0.235 to minimum 0. 063. SEM analyses indicates that the wear scare obtained with fullerene copolymer exhibited mild scratches, while sharp grooving and serious pull-out phenomnon were observed in the presence of base stock without additive .The improvements in friction, wear and load-carrying capacity are probably due to the presence of fullerene copolymer nanoballs, which may act as molecule ball bearings, which in turn lead to elastic rolling lubrication.

关键词： Water-soluble Fullerene copolymer Nanoball Fricition and wear Microcosmic elastic rolling8