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Textures and Magnetic Properties of Grain Oriented ElectricalSteel Produced by Cross Shear Rolling

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Journal of Materials Science & Technology 1998年第2期14卷 167-170页

作者： Liu, Gang Qi, Kemin Sun, Jianlun Zuo, Liang Liang, Zhide Wang, Fu Northeastern Univ Sch Met & Mat Shenyang 110006 Peoples R China

Commercial grain oriented electrical steels were made by cross shear rolling (CSR) with a chosen mismatch speed ratio 1.1. Original sheets of 0.75 mm thick, which have been produced by conventional cold rolling and intermediate annealing, were rolled to thickness from 0.35 mm to 0.5 mm, and followed by industry annealing. The deformation texture and the magnetic properties were measured. Results indicate that: in the condition of the CSR, the deformation texture of rolled sheet is generally similar to that of conventional rolled sheet; for sheets with the thickness from 0.35 mm to 0.25 mm, favorable deformation textures, mainly consisting of left brace 111 right brace (112), are also found at subsurface layers, which may help to produce sharp Goss texture; and after the final annealing, the magnetic properties of sheets are not lower than that of conventional rolled sheets. (Edited author abstract) 11 Refs.

关键词： Steel

Effect of Prior Deformation on Aging Process in a Cu-30Ni-25Fe Spinodal Alloy

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Journal of Materials Science & Technology 1999年第6期15卷 519-522页

作者： Hao, XJ Li, HX Zhao, G Hao, SM Northeastern Univ Sch Met & Mat Shenyang 110006 Peoples R China

The effect of prior deformation on the mechanical properties and microstructural evolution of aging process in a Cu-30Ni-25Fe (in at. pct) alloy has been studied by tensile test, hardness measurement, SEM and optical microscopy analysis. The results show that spinodal decomposition and recovery process interact on each other when aged at low temperature (600 degrees C), and most of the defects induced by cold-work did not disappear in 100 h. When aged at high temperature (850 degrees C), the discontinuous coarsening of the spinodal products takes place. The increase in yield strength and elongation of the sample aged at 850 degrees C for 5 h after deformation mainly results from the submicromet.r grains produced by discontinous coarsening of spinodal products.

关键词： Copper alloys

Magnetic Properties of Nd_8Fe_(83)Co_3B_6 Nanocomposite Magnets

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Journal of Materials Science & Technology 2000年第2期16卷 109-110页

作者： Fazeng LIAN, Guiqin ZHOU, Wenli PEI and Xueqin YAN (sch.ol of Materials and met.llurgy, Northeastern University, Shenyang 110006, China) Northeastern Univ Sch Met & Mat Shenyang 110006 Peoples R China

The influence of quenching technology, annealing temperature and time on the structures and magnetic properties of Nd_8Fe_83C_o_3B_6 nanocomposite magnets was investigated. The results show that the α-Fe/Nd_2 Fe_14 Bnanocomposite magnet containing a small amount of B is difficult to form amorphous state. The magnetic properties of 26 m/s quenched Nd_8Fe_83C_o_3B_6 powders annealed at 640℃×480 s reach _iH_c=513 kA/m, B_r=1.05 T and (BH)_max=92.0 kJ/m^3. The grain size is D_a-fe=21.5 um and D_Nd_2Fe_14B=30.2um.

关键词： Magnetic Properties of Nd8Fe Nd than rate

Leakage in Mold Slit during Inverse Solidification

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Journal of University of Science and Technology Beijing 2001年第2期8卷 101-104页

作者： Zhang, JM Wang, XH Wang, WJ Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China

The liquid steel will be leaked from the slit between the bottom of solidification mold and mother sheet during inversion casting process. By substitution of the actual liquid steel, the Ph-Sn alloy and the numerical simulation can be used to study the fluid flow in the inversion solidification mold, the mother sheet critical speed is determined for preventing the leakage from the slit of bottom. When the mother sheet speed is more than 0.06 m/s, Pb-Sn liquid alloy will not leak from the slit of the mold. Otherwise, the Ph-Sn liquid alloy can leak from the slit of the mold.

关键词： leakage slit inverse solidification mold

Effect of Rare Earth Elements on Transformation Behavior and Microstructure Characteristics in X80 Pipeline Steel

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稀有金属材料与工程 2011年第S3期40卷 51-55页

作者： Liu Chengjun, Liu Hongliang, Jiang Maofa Northeastern University, Shengyang 110004, China Northeastern Univ Sch Met & Mat Shenyang 110004 Peoples R China

The studies of the rare earth elements (RE) in low carbon steels suggest that the RE inhibits the ferrite transformation, which is the same effect as Mo alloying in pipeline steels. The purpose of this work is to discuss the relationships between the RE microalloying and the microstructure in pipeline steels. The X80 pipeline steels with different RE and Mo additions have been produced by vacuum induction furnace. The Gleeble-2000 thermal simulator, optical microscopy, and scanning electron microscopy with EBSD have been used. The continuous cooling transformation (CCT) curve was obtained and analyzed, combined with the study of microstructure. The results indicate that the microstructure of thermal simulator test met.l is characteristic of quasi-polygonal ferrite and bainite, and trace RE could significantly inhibit the transformation of quasi-polygonal ferrite. The 0.0040wt% content of RE plays the same role as 0.1 wt% content of Mo alloying in pipeline steels. What’s more, the fine bainite grained structure is obtained with RE microalloying. Theoretically RE could be employed in pipeline steels as microalloying, and a partial substitution of Mo by RE is possible.

关键词： rare earth elements pipeline steel transformation microstructure CCT

Micro-alloying of Rare Earths in Heavy Rail Steel

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稀有金属材料与工程 2011年第S3期40卷 245-249页

作者： Huang Yahe, Liu Chengjun, Jiang Maofa Northeastern University, Shenyang 110819, China Northeastern Univ Sch Met & Mat Shenyang 110819 Peoples R China

In the present study, heavy rail steel was prepared by the process of vacuum induction furnace smelting, forge work and rolling. Effects of Rare earths (RE) on microstructure and mechanical properties of heavy rail steel were systematically investigated by met.llographic microscope, SEM, integrated mechanical testing machine, impact tester and so on. met.llographic analysis shows that, a few of RE can evidently delay the growth of austenite grain and fine pearlite. When the RE content is 0.016%, both annealing and normalizing pearlite laminae distances reach the minimum which is 115 nm (annealing) and 104nm (normalizing), respectively. But when the RE content reaches 0.133%, the annealing and normalizing pearlite laminae distance is respectively increased by 40% and 13%. Mechanical properties tests show that, a few of RE has not notable effect on the strength, but both plasticity and ductility can be improved obviously. When the RE content is 0.016%, both plasticity and ductility reach maximum. The maximum of elongation and reduction of area is 13.3% and 29.0%, respectively. However, when the RE content reaches 0.133%, the strength, plasticity and ductility are decreased. Especially, the low temperature (-40 ℃) and room temperature (20 ℃) ballistic work is respectively decreased by 9% and 24.8%.

关键词： rare earths heavy rail steel austenite pearlite mechanical properties

Precipitates in an isothermally aged Fe-18Cr-12Mn-0.04C-0.48N high-nitrogen austenitic stainless steel

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Rare met.ls 2007年第S1期26卷 185-190页

作者： SHI Feng,WANG Lijun,CUI Wenfang,REN Yuping,LI Hongxiao,and LIU Chunming sch.ol of Materials & met.llurgy,Northeastern University,Shenyang 110004,China Northeastern Univ Sch Met & Mat Shenyang 110004 Peoples R China

Vertical section of Fe-18Cr-12Mn-0.04C-N system phase diagram varying with nitrogen content at 1×105 Pa was calculated using Thermo-Calc software and thermodynamic *** morphology and crystallography information of precipitates in Fe-18Cr-12Mn-0.04C-0.48N high-nitrogen austenitic stainless steel during isothermal aging at 800 ℃ after austenization was investigated using optical microscopy(OM),and transmission electron microscopy(TEM) with energy distribution spectrum(EDS).The experimental results show that three precipitates,(Cr,Fe,Mn)2(N,C),(Cr,Fe,Mn)23(C,N)6 and σ phase exist in this steel,which is consistent with the thermodynamic calculation,indicating that thermodynamic calculation can provide instructions for alloy composition design,heat treatment and prediction of precipitation sequence in Fe-18Cr-12Mn-0.04C-N system.

关键词： precipitate isothermal aging thermodynamic calculation phase diagram high nitrogen austenitic stainless steel

Effects of electric-field treatment on a Ni-base superalloy

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Rare met.ls 2007年第S1期26卷 210-215页

作者： WANG Lei,LIU Yang,CUI Tong,and ZHAO Xiang sch.ol of Materials and met.llurgy,Northeastern University,Shenyang 110004,China Northeastern Univ Sch Met & Mat Shenyang 110004 Peoples R China

The effects of electric-field treatment on the microstructure and deformation behavior of a nickel-base superalloy were *** results show that the electric-field treatment increases the ductility of the superalloy but has no evident influence on its static strength at both room and elevated temperatures,while,the strength increases but elongation changes weekly with the increasing tensile strain *** is found that the direction of microcrack propagation can be changed by the presence of the annealing twins during the tensile deformation,and it causes the increasing of the plastic deformation energy and delay of the fracture,which is considered as the reason for the increasing the ductility.

关键词： electric-field treatment nickel-base superalloy annealing twin deformation behavior strain rate

Mechanical Behaviour and Microstructure Evolution of Superplastic Mg-8.4 wt pct Li Alloy and Effect of Grain Size and Phase Ratio on Its Elongation

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Journal of Materials Science & Technology 2000年第1期16卷 55-58页

作者： Cao, FR Cui, JZ Wen, JL Lei, F Northeastern Univ Sch Met & Mat Dept Mat & Forming Control Shenyang 110006 Peoples R China

Mechanical properties and microstructure evolution of Mg-8.4 wt pet Li alloy have been investigated. The superplastic elongation-to-failure 920% at 573 K and initial strain rate of 5 x 10(-4) s(-1) at low nominal stress 2 MPa has been demonstrated. It was shown through optical microstructure that the average grain sizes at gauge length section before and after superplastic tension and at grip section were 7.5 mu m, 31.7 mu m and 20 mu m respectively, indicating significant deformation induced grain growth and static grain growth. Comparison of experiment data with published data for superplastic Mg-Li alloys shows that fine grain size and about 50 to 50 phase ratio contribute to achieving the largest superplasticity. Some related research works in other alloys are compiled and further evidences to such theoretic argument are provided.

关键词： Magnesium alloys