LIU Ning CUI Kun Huazhong University of Science and Technology
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Wuhan.China DENG Zonggang Hefei University of Technology
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Hefei
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China CHENG Benpei KONG Jie Institute of Solid State Physics
,
Academia Sinica
,
Hefei
,
China Doctorate student
,
Department of Mechanical Engineering No.2
,
Huazhong University of Science and Technology
,
Wuhan 430074
,
China
金属学报(英文版)
Microstructure of the deepest zone of high speed steel W6Mo5Cr4V2(M2)melt after laser fu-sion was found to be so fine as the ehill zone of a solidified ingot.When narrower chill zoneformed,the long columnar dendrites grow into the melt and then the fine equiaxed cellularstructure appears in upper melt region nearly surface.The substructure of cellular grains anddendrites was observed to consist of martensite and retained austenile,while the carbides asM_6C_■ Cr_7C_3 and MC distributed at their boundaries.It is believed that the highermicrohardness up to HV_(0.1)=865-960 of the laser fused structure of the alloy is due to the oc-currence of martensite.
关键词:
High speed steel W6Mo5Cr4V2(M2)
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null
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null
TAO Zengyi LUO Jiaming Huazhong University of Science and Technology
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Wuhan
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China TAO Zengyi
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Faculty of Metallic Materials
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Dept.of Mechanical Engineering No.2
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Huazhong University of Science and Technology
,
Wuhan 430074
,
China
金属学报(英文版)
The influence of laser surface melting and induction hardening on the surface structure,con- tact fatigue life and failure behaviour of the nodular cast iron has been investigated.The con- tact fatigue life can be improved by both laser treatment and induction hardening,but the fail- ure process and type are different from each other.The former is due to lumpy and deep spal- ling caused by crack propagation between the quenching zone and the substrate,and the latter is due to nubby and surface flaking caused by the oil wedged action into surface cracks.
关键词:
surface hardening
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null
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null
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null
XIE Changsheng SUN Peizhen ZHAO Jiansheng CHEN Yuqiu Huazhong University of Science and Technology
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Wuhan
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China XIE Changsheng Associate Professor
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Department of Mechanical Engineering No.2
,
Huazhong University of Science and Technology
,
Wuhan 430074
,
China
金属学报(英文版)
The microstructures of Fe-Mn-Ni-Cr steels with medium carbon and the effect of alloy ele- ments on them have been investigated by means of X-ray diffraction quantitative phase ana- lyses,metallography and hardness tests.The volume fraction of martensite in steels quenched at 1100℃ can be expressed as: f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V) Based on this expression,the quasi-equilibrium microstructure diagram has been obtained.It is shown that the effect of Mn on the austenite stability is greater than that of Ni.The equiva- lent [Ni]=2.104Mn+Ni and equivalent [Cr]=Cr+Mo+V. The driving force for martensite transformation at M_s point has been calculated to he drastically decreased by element Mn.
关键词:
quasi-equilibrium microstructure diagram
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null
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null
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null
ZHANG Shourong
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) No5 at WISCO (Wuhan Iron and Steel Corporation), and in October, 1991, the BF No5 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 No5 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
TAN Wen
,
HAN Bin
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WANG Shui-ze
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YANG Yi
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ZHANG Chao
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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
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mechanical property
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banding microstructure
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processing-parameter
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
