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Atomic Structure and Doping Response of Grain Boundary in Transition Metal Ni

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Science China Mathematics 1994年第7期37卷 878-890页

作者：王崇愚于涛 International Centre for Materials Physics Academia Sinica Shenyang 110015 and Central Iron Steel Research Institute Beijing 100081 PRC central iron and steel research institute Beijing 100081 PRC

Based on the coincidence site lattice model and by use of the molecular dynamics method, the relaxation calculations on the atomic structures of the grain boundaries of various generating functions (∑3,∑5,…, ∑19,…,∑33) in the transition metal Ni are performed. The features of atomic structures corresponding to the grain boundaries and the effects of the pre-parameter on the interface structures are given. To study the doping response relating to the properties of materials, the 23 tilt grain boundary is selected. Based on the interstice and vacancy mechanisms, the interface responses doping boron, nitrogen and phosphorus for the grain boundary are investigated. According to the criterion of the energy in molecular dynamics simulation, the most probable positions of doping impurities and effect of doping impurities on the interface structure are given, and the dependence of the fine structure on doping type and the order of the impurity amount are obtained. The analysis of the local energy for the relaxation region shows that the light impurities, boron, nitrogen and phosphorus, all have a tendency to segregate on the grain boundary and change the feature of the atomic configuration of the interface to a distinct extent. Then the effects of doping impurities on the interface can be predicted.

关键词： atomic structure of grain boundary doping response molecular dynamics method.

Original position statistic distribution analysis study of low alloy steel continuous casting billet

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Science China(Technological Sciences) 2005年第1期48卷 104-115页

作者： WANG Haizhou ZHAO Pei CHEN Jiwen LI Meiling YANG Zhijun WU Chao central iron & steel research institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China

The homogeneity of low alloy steels continuous casting billet obtained under different technological conditions has been investigated by original position statistic distribution analysis technique. On the basis of systematic analysis of ten thousands primary optical signals at the corresponding original positions, the quantitative statistic distribution information of each element was obtained. The biggest degrees of segregation of low alloy steel continuous casting billet were calculated accurately according to the quantitative distribution maps of the contents. It was suggested that the weight ratio in a certain content range was used to judge the homogeneity of the materials, and the two models —— the total weight ratio of contents (the degree of statistic homogeneity, H) within the permissive content range (C0±R) and the median value confidence extension ratio (the degree of statistic segregation, S) at 95% of confidence limit of weight ratio —— were put forward. The two models reflect the composition and state distribution regularity of the metal materials in a large region. The difference between the sample with high columnar crystal and the sample with high equiaxed crystal has been studied by using the two models.

关键词： original position statistic distribution analysis, equiaxed crystal, columnar crystal, degree of statistic homogeneity.

Electronic Structure of Edge Dislocation in iron

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Science China Mathematics 1993年第10期36卷 1261-1272页

作者：王崇愚岳勇曾跃平刘福绥 International Centre for Materials Physics Academia Sinica and Central Iron and Steel Research Institute Beijing 100081 PRC central iron and steel research institute Beijing 100081 PRC Department of Physics Peking University Beijing 100871 PRC

Based on the elasticity theory and considering the lattice modification for dislocation core, the primary atomic coordinates of edge dislocation core in iron are given. On the basis of the primary atomic configuration and the self-consistent calculation performed by using the molecular dynamics, the relaxed atomic structure of the dislocation core is set up. From the modified atomic coordinates and by use of the recursion method, the electronic structure of the system is calculated and it is found that the edge dislocation results in the splitting of degenerate states, and the movement of Fermi level. Meanwhile, the change of Fermi level caused by deformation in crystal is also calculated. Based on the expression given by us, the charge redistribution of the dislocation core is obtained and the trapping effect of the dislocation core on impurity predicted.

关键词： dislocation core electronic structure.

ELECTRONIC STRUCTURE OF GRAIN BOUNDARY IN TRANSITION METAL Ni

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Science China Mathematics 1992年第12期35卷 1466-1474页

作者：王崇愚曾跃平 International Centre for Materials Physics Academia Sinica and Central Iron and Steel Research Institute Beijing 100081 PRC central iron and steel research institute Beijing 100081 PRC

Based on the coincidence site lattice model and by use of the molecular dynamic method for relaxing the atoms in the grain boundary, the atomic coordinates of Σ5 grain boundary are presented. And the recursion method is utilized to calculate the electronic structures of crystal transition metal Ni and the transition metal Ni containing the grain boundary. The grain boundary energy, bond order, the interaction between atoms and the charge transfer are obtained. Meanwhile, we defined the electronic *** results show that the relaxed Σ5 grain boundary may possibly exist and have the ability to trap *** with that of the crystalline Ni,the interatomic force in the grain boundary tends to decrease, meaning that the grain boundary belongs to a kind of structure with weak connection.

关键词： electronic structure recursion method and grain boundary energy.

Analysis of NdFeB multi-pole ring by SEM and MFM

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Rare Metals 2006年第Z1期25卷 489-492页

作者： LIU Xingmin LI Xiumei FANG Yikun ZHU Minggang HAN Baoshan LI Wei central iron & steel research institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China Central Iron & Steel Research Institute Beijing 100081 China State Key Laboratory of Magnetism Institute of Physics and Center of Condensed Matter Physics CAS Beijing 100080 China Central Iron & Steel Research Institute Beijing 100081 China

Sintered multi-pole ring that is made in America and China was analysed by SEM and MFM. The results show that the average size of American multi-pole ring is much smaller than the Chinese one and has much better orientation degree. The magnetic field of American specimen is much higher than that of the Chinese one and its average value is about 500 Gs, and more uniform distribution of the Nd-rich phase has been obtained.

关键词： ring NdFeB SEM

Effects of Re, Ta, and W in [110] (001) dislocation core of γ/γ' interface to Ni-based superalloys: First-principles study

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Chinese Physics B 2020年第9期29卷 390-396页

作者： Chuanxi Zhu Tao Yu central iron and steel research institute Beijing 100081China

The strengthening effects of alloying elements Re,Ta,and W in the[110](001)dislocation core of theγ/γ'interface are studied by first-principles *** the level of energy the substitution formation energies and the migration energies of alloying elements are computed and from the level of electron the differential charge density(DCD)and the partial density of states(PDOSs)are *** elements above are found to tend to substitute for Al sitesγ'phase by analyzing the substitution formation *** calculation results for the migration energies of alloying elements indicate that the stability of the[110](001)dislocation core is enhanced by adding Ta,W,and Re and the strengthening effect of Re is the *** results agree with the relevant *** electronic structure analysis indicates that the electronic interaction between Re-nearest neighbor(NN)Ni is the *** reason why the doped atoms have different strengthening effects in the[110](001)dislocation core is explained at the level of electron.

关键词： Ni-based superalloys dislocation structure electronic structure first-principles calculations

Review on the study of metallurgical process engineering

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International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1253-1263页

作者： Rui-yu Yin central iron and steel research institute Beijing 100081China

After nearly one hundred years of research, metallurgy(metallurgical science and engineering) has gradually become a system with three levels of knowledge:(1) micro metallurgy at the atomic/molecular scale,(2) process metallurgy at the procedure/device, and(3) macrodynamic metallurgy at the full process/process group. Macro-dynamic metallurgy development must eliminate the concept of an "isolated system" and establish concepts of "flow," "process network," and "operating program" to study the "structure–function–efficiency" in the macrodynamic operation of metallurgical manufacturing processes. It means considering "flow" as the ontology and observing dynamic change by"flow" to solve the green and intelligent potential of metallurgical enterprises. Metallurgical process engineering is integrated metallurgy, toplevel designed metallurgy, macro-dynamic operated metallurgy, and engineering science level metallurgy. Metallurgical process engineering is a cross-level, comprehensive, and integrated study of the macro-dynamic operation of manufacturing processes. Metallurgical process engineering studies the physical nature and constitutive characteristics of the dynamic operation of steel manufacturing process, as well as the analysis-optimization of the set of procedure functions, coordination-optimization of the set of procedures' relations, and reconstruction-optimization of the set of procedures in the manufacturing process. The study establishes rules for the macro operation of the manufacturing process, as well as dynamic and precise objectives of engineering design and production operation.

关键词： metallurgical process engineering cross-level comprehensive integration macro-dynamic operation new branch of metallurgy

Oxidation Behavior of Fe-based Amorphous Ribbons

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Journal of iron and steel research International 2016年第11期23卷 1219-1225页

作者： Shu-lan ZHANG He-ping LIU Xiao-tong FU central iron and steel research institute Beijing 100081China

The oxidation behavior of Fe-based amorphous ribbons was tested by annealing at 380℃ in air for different time with heat treatment furnace and analyzed by X-ray photoelectron spectroscopy （XPS） and scanning electron micros- copy （SEM）. The mechanism of oxides formation of the amorphous ribbons was discussed in detail. The results showed that the oxides were mostly B2O3 , SiO2 and Fe2O3 or FeO. With the increase of annealing time and holding temperature, the fraction of the oxides on the ribbon surface increased and the size of the oxides became larger due to the generation of new oxides and the coalescence of small oxides. The oxides have different shapes, such as round, rod and needle-shaped. Experimental results also showed that the oxides nucleated at fish scale, air pocket and impu-rities in priority, and the growth of the oxides was controlled by the diffusion of atoms. With the increase of the distance to the ribbon surface, the oxygen concentration decreased dramatically. Due to the low binding energy of B2O3 and the large diffusion coefficient of B atom, the B elemaent was oxidized firstly compared with other elements. More- over, the oxidation deoths of the B2O3 and SiO2 were larger than that of Fe2O3.

关键词： oxidation amorphous ribbon nucleation~ oxide growth

Surface microstructure control of microalloyed steel during slab casting

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Journal of iron and steel research International 2017年第8期24卷 803-810页

作者： Li-jun Xu Shu-lan Zhang Chun-gen Qiu Sheng-tao Qiu Xing-zhong Zhang central iron and steel research institute Beijing 100081China

Lots of work has been done to investigate slab surface microstructure evolution during continuous casting in order to improve hot ductility and avoid transverse *** slab surface microstructure after continuous casting was characterized by optical microscopy,and the precipitation behavior was investigated by transmission electron *** the same time,the mechanical properties of the slabs were measured using a Gleeble 1500 Dthermal simulator and the transformation temperatures were examined by means of a thermal *** experimental results show that homogeneous microstructure without film-like ferrites and chain-like precipitates at grain boundary can be obtained through surface intensive cooling and transverse cracks do not occur on the slab *** the experimental steel,fine ferrite can form at slab surface when the water flow rate is larger than 1560L/min at vertical *** the distance to surface increases,microstructure turned to ferrite and ***,nano-size carbonitrides precipitated in the ferrite grain and the size was larger at the junction of the *** mechanical experiment results show that the hot ductility of the sample deformed at 650°C was better than that of the sample deformed at 750°*** reason is that filmlike ferrite formed at the grain boundary in the sample deformed at 750°***,the slab must be cooled quickly below Ar3 to prevent the occurrence of film-like ferrite and transverse cracks on the slab surface during casting.

关键词： Microalloyed steel Surface intensive cooling Ferrite Carbonitride Crack