材料期刊网

Microstructure and Mechanical Properties of a Duplex Martensite Austenitic Steel Precipitation-hardened by VC Carbide

Changsheng XIE , Jiansheng ZHAO , Peizhen SUN , and Xia LIANG (Dept.of Mech. Eng. Ⅱ , Huazhong University of Science and Technology , Wuhan , 430074 , China)(To whom correspondence should be addressed)

材料科学技术（英文）

This paper presents an investigation on the primary microstructure and mechanical properties of a martensite-austenitic duplex steel precipitation-hardened by VC carbide. The results show that the mechanical properties at room temperature are strongly dependent upon the volume fraction of austenite fA. When fA < 32 % both ultimate strength and Vield strength are decreased with increasing fA. however. whenfA>32%, with increasing the.fA. ultimate strength rises and yield strength drops down. Experimental results at elevated temperatures. show that when test temperature ≤500℃. the yield strength to modulus ratio remains unchanged, however. as the temperature rises a substantial fall in the ratio occurs. The strength values at 600 and 700℃ are increased with increasing strain rate measured by cross-head speed of testing rnachine, The law of mixtures and the contribution of strain-induced transformation from unstable austen ite to martensite to the mechanical properties are discussed.

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Fracture Behaviour of Laser Clad Fe- and Ni-base Alloy Coatings on a Cast Iron under SEMI Loading

Aihua WANG , Changsheng XIE , Kaijin HUANG , Beidi ZHU and Zengvi TAO (Dept. of Materials Science & Engineering , Huazhong University of Science & Technology , Wuhan , 430074 , China)

材料科学技术（英文）

Laser cladding technique has been applied to renovate some partially-damaged (or worn) components with Fe, Ni, Co-base alloys, hence to improve their hardness values and wear resistance successfully in previous reports. But for some punching or shearing cast iron dies damaged or worn in automobile manufacture, the renovated surfaces also bear some impact loading. Therefore, a small-energy and multi-impact (SEMI) test was designed to investigate the fracture behaviour of renovated cast iron dies achieved by laser cladding of Fe and Ni-base alloys under SEMI loading to meet above requirement. observations show that the fracture took place in the substrate near to the substrate/coating interface rather than at the interface. The tempering temperature has a great influence on the cycles to fracture of laser-clad samples under SEMl loading, i.e. the low tempering temperature of 300℃ gives a maximum cycle to fracture, while a higher tempering temperature of 400℃ has a minimum. Furthermore, the fracture mechanism has also been discussed in present study

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Practice for Extending Blast Furnace Campaign Life at Wuhan Iron and Steel Corporation

ZHANG Shourong

钢铁研究学报(英文版)

One of the problems encountered in 60′s to 80′s of 20th century in China′s steel industry was short life of blast furnace shaft as well as the excessive erosion of blast furnace hearth. A series of research work was carried out in order to extend blast furnace campaign life. The concept of research and development was integrated in the construction of BF (blast furnace) No5 at WISCO (Wuhan Iron and Steel Corporation), and in October, 1991, the BF No5 was blown in. The blast furnace has worked smoothly for more than 15 years without any medium repair even guniting. It is expected that the campaign life of BF No5 would be longer than 16 years with a production over 11 000 t per unit inner volume (m3). A new blast furnace with an inner volume of 3 400 m3 is under construction, and is designed with a campaign life of 20 years without any medium repair. The campaign life of blast furnaces in China has been extended in recent years.

关键词: blast furnace;campaign life;erosion

Preparation and Gas-sensing Characteristics of Na~+-doped ZnO Single Crystals

Suying PAN and Junbiao MAO (Center for Materials Research and Analysis , Wuhan University of Technology , Wuhan , 430070 , China)(To whom correspondence should be addressed)

材料科学技术（英文）

ZnO single crystals were grown by vapor phase reaction of Zno powder with active carbon powdei at an elevated temperature The typical crystals were colorless and transparent with maximum size o4 0.1 mm in diameter and 25 mm in length, The gas-sensing characteristics of Na+-doped anc undoped single crystals were investigated in 1 %H2. Co and CH, in air between 1 50 and 600℃. It was found that the undoped ZnO single crystals showed little gas sensitivity in air. and Na+-doping can greatly enhance the senstivity by increasing the resistivities. The maximum sensitivity of the samples is 22 (Ra/ Rg) for H2. 1 2 for CO and 4 for CH4

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Practice for Extending Blast Furnace Campaign Life at Wuhan Iron and Steel Corporation

钢铁研究学报(英文版)

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欢迎投稿、订阅《Journal of Wuhan University of Technology-Materials Science Edition》

武汉理工大学学报-材料科学版(英文版)

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Application of Low-penetration Concrete as the Protecting Layer in Wuhan Yangtse River Tunnel Tube

武汉理工大学学报-材料科学版(英文版)

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Effects of TMCP Parameters on Microstructure and Mechanical Properties of Hot Rolled Economical Dual Phase Steel in CSP

TAN Wen , HAN Bin , WANG Shui-ze , YANG Yi , ZHANG Chao , ZHANG Yong-kun

钢铁研究学报(英文版)

Effects of chemical compositions, finish rolling temperature, isothermal temperature on runout table and coiling temperature on microstructure and mechanical properties of economical dual phase steel produced on CSP line were investigated. Experimental results showed that martensite volume fraction could be enhanced and banding microstructure could be reduced by controlling Mn, Si contents and applying proper finish rolling temperature. Optimized processing-parameters were obtained for DP580 production on CSP line of Wuhan Iron and Steel (group) Co (WISCO) in China. Optimal microstructure and mechanical properties could be achieved when the strip was finished rolling at the range of 790 to 830 ℃, isothermally holding at 680 to 740 ℃ and coiling below 250 ℃.

关键词: economical dual phase steel , mechanical property , banding microstructure , processing-parameter

Reply to "Comment on 'Low-temperature lattice excitation of icosahedral Al-Mn-Pd quasicrystals' "

Physical Review B

In response to the comment by Wang and Qin, we have rewritten our equation (22) following the coordinate system of Dina, et al. [J. Wuhan Univ. (Nature Science Edition) 3, 23 (1992)]. According to the thermodynamic stability condition and the experiment of Capitan et al., we have chosen the new parameters of the phason elastic constants. Based on this, we have recalculated the coefficients of the expressions on the vibrational denty of states and the specific heat of the icosahedral Al-Nin-Pd quasicrystal. Our results are still in agreement with the experimental data measured by Walti et al. [Phys. Rev. B 57, 10 504 (1998)]. It demonstrates that our method is useful for dealing with the low-temperature vibrational excitation of icosahedral quasicrystals.

关键词: quasi-crystals;diffuse-scattering

Treatment of Reused Comprehensive Wastewater in Iron and Steel Industry With Electrosorption Technology

ZHANG Yunhua , GAN Fuxing , LI Meng , WANG Dihua , HUANG Zhongmai , GAO Yunpeng

钢铁研究学报(英文版)

Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant of WISCO [Wuhan Iron and Steel (Group) Corporation]. The results of the onsite industrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580-780 μS/cm to 100-350 μS/cm. The average removal efficiency of Cl- and Ca2+ was about 75% and 68%, respectively, and CODCr of the treated water was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 06 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel electrosorption technology can be used in enhanced desalination and purification treatment of reused comprehensive wastewater in iron and steel industry.

关键词: electrosorption , desalination , purification , conductivity , industrial reused water