DING Hua
,
TANG ZhengYou
,
LI Wei
,
WANG Mei
,
SONG Dan
钢铁研究学报(英文版)
The mechanical properties and microstructure of two low carbon high manganese steels with 238% (No1) and 33% (No2) (mass percent) of manganese were investigated. The results showed that No1 steel possesses high strength and high plasticity, and No2 steel has a relatively high strength and extraordinary plasticity. The No1 steel exhibits both TRIP (transformation induced plasticity) and TWIP (twin induced plasticity) effects during the deformation; while only TWIP effect appeared under the same deformation condition for No.2 steel. The comparison between the microstructures and mechanical properties of two steels was made, and the strengthening mechanisms were also analyzed.
关键词:
manganese;TRIP;TWIP;microstructure;mechanical property
马乾志
,
郭杨龙
,
王艳芹
,
郭耘
,
张志刚
,
卢冠忠
无机材料学报
doi:10.3321/j.issn:1000-324x.2007.05.033
采用TS-1前驱体作硅源和钛源,以十二胺为模板剂,在中性和室温条件下合成了介孔含钛分子筛Ti-HMS-1.采用XRD、TEM、低温N2吸附、FT-IR和UV-Vis等方法对合成的分子筛进行了表征;以苯乙烯的催化氧化反应为模型反应,考察了合成的Ti-HMS-1的催化氧化性能.结果表明,Ti-HMS-1具有"worm-like"介孔结构,但长程有序度较低,孔壁部分含有MFI的次级结构单元,在373K沸水中水煮50h后,Ti-HMS-1仍能较好地保持原有的介孔结构,表明Ti-HMS-1具有较高的水热稳定性.进入分子筛骨架的钛原子为催化剂的活性中心,对于苯乙烯氧化反应,具有较高的催化活性,对产物的选择性与Ti-HMS接近.
关键词:
Ti-HMS-1分子筛
,
合成
,
表征
,
苯乙烯氧化
刘守平
,
周上祺
,
王佳眉
,
任勤
腐蚀科学与防护技术
用金相显微镜、扫描电镜、X射线衍射仪和X射线能谱仪对天然气井油管悬挂器腐蚀失效进行了检测分析，并对天然气井油管悬挂器用35CrMo钢进行了盐雾试验，结果表明，天然气中的水和CO2是引起腐蚀的主要介质，腐蚀产物主要是FeCO3，高速天然气冲刷和钢中的非金属夹杂加剧了腐蚀的速度.
CORROSION FAILURE ANALYSIS OF AN OIL TUBE USED IN NATURAL GAS WELL
LIU Shou-ping,ZHOU Shang-qi,WANG Jia-mei,REN Qin
Chongqing University
A failed oil tube used in natural gas well was examined by optical microscope,scanning electron microscope ,X-ray diffractometer and X-ray spectrometer.Corrosion behavior of 35CrMo steel samples of the oil tube were investigated by means of salt spray tests in the laboratory.The results show that CO2 and H2O are primary factors in the corrosion of oil tube.The corrosion product is FeCO3,non-metallic inclusions in the steel and erosion of natural gas fluid played an important role in accelerating the corrosion.
oil tube;
natural gas well；
35CrMo steel；
failure analysis；
corrosion
关键词:
悬挂器
,
null
,
null
,
null
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
Journal of Chemical Physics
Based on Mei's embedded atom model [Mei , Phys. Rev. B 43, 4653 (1991)] molecular dynamics simulations have been performed to investigate the rapidly cooling processes of Cu. The atomic transport property, namely the self-diffusion coefficient, is computed in the liquid state, and the results near the melting point of Cu are in good agreement with experimental data and other computational values. The atom diffusion movements during the long period of relaxation have been also studied around the solidification temperature T-c. To describe the complex microstructural evolutions during the rapidly cooling processes and the long relaxation processes, the pair correlation function and the pair analysis technique are used. It is demonstrated that the crystallization of amorphous Cu is caused by the atomic diffusion. (C) 2004 American Institute of Physics.
关键词:
transition-metals;computer-simulation;supercooled-liquid;model;fcc;potentials;diffusion
材料科学技术（英）
The effect of interstitial hydrogen on the cohesion of the Al Sigma=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.
关键词:
hydrogen;grain boundary;Al-Mg alloys;pseudopotentials;1st-principles
Xiaoguang LIU
,
Xiaowei WANG
材料科学技术（英）
The effect of interstitial hydrogen on the cohesion of the Al ∑=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.
关键词:
Hydrogen
,
null
,
null
Physical Review B
By use of the linear-combination-of-atomic-orbital (LCAO) method for a cluster model, we studied the electronic structure of gamma-from Sigma 11 [1 (1) over bar0](11 (3) over bar) grain boundary doping with N and Mn atoms. The effect of the segregation on the cohesion of the grain boundary is investigated based on the Rice-Wang thermodynamic model. It is found that N could not only largely enhance the cohesion of the grain boundary but also eliminate the detrimental effect of Mn. The cosegregation effect of Mn and N on the cohesion of the grain boundary depends on where they segregate. Nitrogen could be reliably used in alloyed steels as an efficient strengthening element.
关键词:
electronic-structure;phosphorus segregation;stainless-steel;embrittlement;austenite;nitrogen;boron;impurities;fracture;metals
Journal of Physics and Chemistry of Solids
The layered ternary ceramics Ti3SiC2 and Ti3AlC2 are isostructural and can form Ti3Si1-xAlxC2 solid solutions combining the advanced properties of both compounds [H.B. Zhang, Y.C. Zhou, Y.W. Bao, M.S. Li, Improving the oxidation resistance of Ti3SiC2 by forming a Ti3Si0.90Al0.1C2 solid solution, Acta Mater. 52 (2004) 3631-3637; E.D. Wu, J.Y. Wang, H.B. Zhang, Y.C. Zhou, K. Sun, Y.J. Xue, Neutron diffraction studies of Ti3Si0.9Al0.1C2 compound, Mater. Lett. 59 (2005) 2715-2719; J.Y. Wang, Y.C. Zhou, First-principles study of equilibrium properties and electronic structure of Ti3Si0.75Al0.25C2 solid solution, J. Phys.: Condens. Matter 15 (2003) 5959-5968; Y.C. Zhou, J.X. Chen, J.Y. Wang, Strengthening of Ti3AlC2 by incorporation of Si to form Ti3Al1-xSixC2 solid solutions, Acta. Mater. 54 (2006) 1317-1322]. In the present work, the solid solutions of Ti3Si1-xAlxC2 (x = 0, 0.25, 0.33, 0.5, 0.67, 0.75, 1) are investigated by first-principle calculations based on pseudo-potential plan-wave method within the density functional theory framework. The results show that as Al content increases in the solid solution, all the bonds have weakened to certain extents, which lead to an unstable structure both energetically and geometrically. The calculated results are compared and discussed with the reported data for the Ti3Si1-xAlxC2 solid solutions. (c) 2007 Elsevier Ltd. All rights reserved.
关键词:
ceramics;ab initio calculations;electronic structure;electrical;conductivity;oxidation behavior;mechanical-properties;ti3sic2;temperature;ti3alc2;air;si
