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Analysis of valence electron structure of RE in Solid Solution in Medium and Low Carbon Steel

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Journal of Rare Earths 2004年第2期22卷 282-287页

作者：朱莹光刘艳刘志林刘伟东 Department of Material and Chemical Engineering Liaoning Institute of Technology Jinzhou 121001 (China College of Science Northeastern University Shenyang 110006 ChinaDepartment of Material and Chemical Engineering Liaoning Institute of Technology Jinzhou 121001 (China

According to EET theory, the valence electron structures of RE in the solid solution of austenite, pearlite and martensite were calculated. The influence of RE in solid solution on phase transformation of pearlite and recrystallization of martensite was explained by the valence electron structure data of phases. Calculating results indicate that C element is favorite to enhance the number of RE in the solid solution. RE in the solute solution shortens the incubation period of proeutectoid ferrite, increases its quantity and carbon content, decreases the quantity of pearlite and thickness of its lamellas and lamellar spacing, then the strength and hardness of pearlite are improved and granular pearlite can be obtained. RE dissolved in martensite intensifies martensite, enhances tempering stability of martensite, increases its recrystallization temperature and prolongs the holding time needed during tempering.

关键词： metal materials valence electron structure phase transformation recrystallization rare earths

Study Segregation of Alloying Elements in Continuous Casting Slab with valence electron structure

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Journal of Materials Science & Technology 2004年第4期20卷 421-425页

作者： YahLIU ZhilinLIU ChengweiZHANG YingguangZHU CollegeofScience NortheasternUniversityShenyang110004China LiaoningInstituteofTechnology Jinzhou121001China ChinaNationalOilandGasExplorationandDevelopmentCorporation Beijing100011China

By calculating the electron structures of the phases that phosphor, sulfur and alloying elements dissolving inγ-Fe, the reason why alloying elements can bring centerline segregation in continuous casting slab (CCS) with nA, the number of electrons on the strongest covalent bonds, and the structure formation factor S were investigated, and an electron structural criterion to control and to eliminate the centerline segregation was advanced. Basing on this, the electron structures of a part of rare earth phosphides and sulfides are calculated, the physical mechanism that rare earth elements can control the segregation of phosphor and sulfur is analyzed, and the criterion is well verified.

关键词： valence electron structure Continuous casting slab Centerline segregation Rare-earth elements.

Effect of valence electron structure on Temper Process and Hardness of the Supersaturated Carburized Layer

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Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 127-134页

作者：石巨岩 College of Materials Science and Engineering Taiyuan University of Technology

By measuring the hardness of carburized layer of a new type supersaturated carburizing steel （35Cr3SiMnMoV） at different temper temperature for 2 h, the relationship curve between the carburized layer hardness and the temper temperature is established. The result indicates that the hardness goes down firstly, then up and down, just like a wave consistent with the temperature increase. A secondary hardening peak appears at 570 ℃ or so. Based on Empirical Election Theory （EET） of Solids and Molecules, the valence electron structures （VESs） containing α-Fe-C, α-Fe-C-Me segregation structure units and carbide are calculated. The laws of temper process and hardness change with the temper temperature are explained, and the fact that reconstruction of θ-Fe3C is prior to that of special carbide at high tempering is analyzed with the phase structure formation factor, S, being taken into consideration. Therefore, the laws of temper process and hardness change of supersaturated carburized layer at different temper temperature can be traced back to valence electron structure （VES） level of alloy phase.

关键词： supersaturated carburizing steel temper process valence electron structure hardness

ANALYSIS OF valence electron structure OF Nd2Fe14B DIRECTLY FROM ITS CRYSTAL structure

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中国科学A辑(英文版) 1988年第12期31卷 1487-1494页

作者：张瑞林吴尚才余瑞璜 Institute of Materials Science Jilin University Changchun Institute of Nonferrous Metals Guangzhou Department of Physics Jilin University Changchun

Based on the experimental data of Nd2Fe14B crystal structure reported by J. F. Herbst, the valence electron structure and the magnetic moment structure of crystal Nd2Fe14B have been analysed by the BLD （bond length difference） method of the empirical electron theory of solids and molecules. The hybridization levels of all kinds of elements at various crystallographic sites in the Nd2Fe14B crystal and their corresponding covalent bond networks are selected as B（g）-6, Nd（f）-1, Nd（g）-1, Fe（c）-A15, Fe（e）-A13, Fe（j1）-A10, Fe（j2）-C3, Fe（k1）-A7 and Fe（k2）-A8. The strongest bond has the number of covalent bond electron pairs n3=0.5819. The distribution of charges around various iron atoms is calculated from the valence electron structure of the crystal. The reason why all the iron atomic magnetic moments are arranged along the direction c is explained by making a comparison between the charge distributions above and below the horizontal atomic plane containing Fe atoms. The dependence of the va

关键词： Nd2Fe14B valence electron structure magnetic moment structure.

Tuning the electron structure enables the NiZn alloy for CO_(2) electroreduction to formate

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Journal of Energy Chemistry 2021年第12期30卷 625-632,I0015页

作者： Xiaodong Zhang Yajiao Zhou Hang Zhang Huang Jing Wei Li Kang Liu Hongmei Li Hao Pan Junhua Hu Junwei Fu Shanyong Chen Min Liu School of Physics and electronics Hunan Provincial Key Laboratory of Chemical Power SourcesState Key Laboratory of Powder MetallurgyCentral South UniversityChangsha 410083HunanChina Department of Periodontics&Oral Mucosal Section Xiangya Stomatological HospitalCentral South UniversityChangsha 410008HunanChina School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002HenanChina School of Environment Guangdong Key Laboratory of Environmental Pollution and HealthJinan UniversityGuangzhou 511443GuangdongChina

Formate is an important liquid chemical,which can be produced by electrocatalytic carbon dioxide reduction reaction(CO_(2) RR).Most of the metal catalysts for CO_(2) RR to formate are toxic or noble metals,such as Cd,Hg,Pb and Pd,leading to the environmental pollution or increased production ***,we develop an environmentally friendly and low-cost NiZn alloy catalyst for CO_(2) RR to *** X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM) confirm the alloy structure of the prepared NiZn catalyst. As for a catalyst for CO_(2) RR,the NiZn alloy exhibits the FE_(HCOO)^(-)(Faraday efficiency of HCOO^(-)) of 36±0.7% at-0.9 V *** in 0.1 M KHCO_(3), and remarkable stability for 40,000 s at-0.8,-0.9,-1.0 and-1.1 V ***,*** calculation results indicate that the NiZn alloy exhibits the middle valence electron structure between the Zn and Ni metal,resulting in the favorable pathway for HCOOH formation but unfavorable for the hydrogen evolution reaction and CO *** Ultraviolet Photoelectron Spectroscopy results verify the modulated valence electron structure for NiZn alloy as compared to Ni and Zn,consistent with the theoretical calculation *** work provides new insights into design of alloy catalysts for CO_(2) RR to formate.

关键词： Electrocatalysis CO_(2)reduction reaction Formate NiZn alloy valence electron structure

Calculations of stability of alloyed cementite from valance electron structure

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Journal of Central South University 2017年第2期24卷 259-269页

作者：王红军刘宏玉刘礼曾晓宇卢建夺林冲徐红兵 Department of Physics Wuhan University of Science and Technology Wuhan 430065 China Hubei Province Key Laboratory of Systems Science in Metallurgical Process Wuhan 430065 China School of Remote Sensing and Information Engineering Wuhan University Wuhan 430079 China Department of Physics and Astronomy Clemson University Clemson SC 29634 USA

Based on the empirical electronic theory of solids and molecules （EET）, the actual model for unit cell of cementite （0-FeaC） was built and the valence electron structures （VES） of cementite with specified site and a number of Fe atoms substituted by alloying atoms of M （ M=Cr, V, W, Mo, Mn ） were computed by statistical method. By defining P as the stability factor, the stability of alloyed cementite with different numbers and sites of Fe atoms substituted by M was calculated. Calculation results show that the density of lattice electrons, the symmetry of distribution of covalent electron pairs and bond energy have huge influence on the stability of alloyed cementite. It is more stable as M substitutes for FeE than for Fe1. The alloyed cementite is the most stable when Cr, Mo, W and V substitute for 2 atoms of Fe2 at the sites of Nos. 2 and 3 （or No. 6 and No. 7）. The stability of alloyed cementite decreases gradually as being substitutional doped by W, Cr, V, Mo and Mn.

关键词： valence electron structure alloyed cementite stability density of lattice electrons symmetry of bonds bond energy

electron theory study on the effect of Mn on as-cast structure of Fe-C-Cr-Mn cast irons

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Journal of Harbin Institute of Technology(New Series) 2008年第5期15卷 643-647页

作者：孙志平沈保罗王均刘浩怀杨宏山黄四久 School of Mechanical Engineering Shandong Institute of Light Industry Metal Material Department Sichuan University Sijiu Rare Earth Alloy Foundry

The valence electron structure of alloying austenite of 3C-15Cr high chromium white cast iron with different Mn contents from 1% to 6% is analyzed by BLD method and EET. Results show that the addition of Mn has major influence on the valence electron structure of the alloying austenite, especially on that of Fe-C, Fe-C-Cr and Fe-C-Cr-Mn unit cells of it. The effect becomes weak when Mn content is over 4%. Based on the effect of n~, F~~, the weighting of each unit cell and the degree of undercooling on phase transition of the aus- tenite, we can calculate the retained austenite content of as-cast structure of the high chromium white cast iron. The calculation results coincide well with those of the experiment. The phase transition characters of the austenite in high chromium white cast iron can be forecasted through valence electron structure analysis of alloying austenite by BLD method and EET on the basis of Fe-C-Cr equilibrium phase diagram.

关键词： high chromium white cast iron retained austenite valence electron structure alloying austenite

DETERMINATION AND APPLICATION OF LARSON-MILLER PARAMETER FOR HEAT RESISTANT STEEL 12CrlMoV AND 15CrMo

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 471-476页

作者： R.C.Yang K.Chen H.X.Feng H.Wang State Key Lab. of Advanced Nonferrous Materials Lanzhou University of Technology Lanzhou 730050ChinaState Key Lab. of Advanced Nonferrous Materials Lanzhou University of Technology Lanzhou 730050ChinaState Key Lab. of Advanced Nonferrous Materials Lanzhou University of Technology Lanzhou 730050ChinaState Key Lab. of Advanced Nonferrous Materials Lanzhou University of Technology Lanzhou 730050China

Based on the analysis and processing on relative empirical formula and data, C-values in Larson-Miller (P) expression, P= T(C + Igt), have determined for pearlitic heat resistant steel 12Cr1MoV and 15CrMo(20.62 and 20.30). The simulation experiments of high temperature aging, heated from 1.5 to 873 hours, have been designed and performed for its verification. And in combination with published information and the present nearly quantitative works, it has further been verified that both the degradations of microstructures and mechanical properties show a good accuracy and practicability using the Larson-Miller parameter with the present determined C-values. Finally, the effects of carbon content on C-value are analyzed by the empirical electron theory of solids and molecules (EET).

关键词： pearlitic heat-resistant steel Larson-Miller parameter aging valence electron structure

EFFECT OF HETEROGENEOUS DISTRIBUTION OF C AND ALLOYING ELEMENTS ONγ/α′TRANSFORMATION IN A Fe-Mn-Cr-C ALLOY

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Acta Metallurgica Sinica(English Letters) 1991年第6期4卷 467-470页

作者： ZHENG Yangzeng ZHANG Fucheng Yanshan University QinhuangdaoChina

The heterogeneous distribution of C and metallic alloying elements as well as the phase com- position changes before and after cold deformation of an Fe-Mn-Cr-C alloy have been stu- died by the use of Mssbauer *** austenites without and with C and metallic alloying elements are found in the alloy in as-solid solution *** the martensites with- out and with C and alloying elements may be induced by cold *** transforma- tion from austenite to martensite in the alloy is confirmed via theoretical computation and ex- periments to be controlled by the number of covalent electron pairs forming covalent bond in austenitic crystal cell of the *** formation of strong covalent bond between C and me- tallic elements can vigorously retard the γ/α' transformation.

关键词： heterogeneity solid solution Mossbauer spectroscopy strain induced martensite valence electron structure