检索结果-南通市图书馆

thermodynamic model for precipitation of carbonitrides in microalloyed steels and its application in Ti-V-C-N system

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2016年第10期35卷 735-741页

作者： Yan-Lin Wang Long-Chao Zhuo Ming-Wen Chen Zi-Dong Wang School of Materials Science and Engineering Tsinghua University School of Materials Science and Engineering University of Science and Technology Beijing School of Materials Science and Engineering Xi'an University of Technology School of Mathematical and Physical Sciences University of Science and Technology Beijing

Based on mass balance and solubility product equations, a thermodynamic model enabling the calcula- tion of equilibrium carbonitride composition and relative amounts as a function of steel composition and tem- perature was developed, which provides a method to es- timate the carbonitride complete dissolution temperature for different steel compositions. Actual carbonitride pre- cipitation behavior was further verified in Ti-V-C-N microalloyed steel system. The model suggests that for higher IV] and [Ti] dissolved in steels, it is available to decrease the addition of C and N during alloy composi- tion design. The resultant longer fatigue life of the modified steel could be attributed to the more [V] and [Ti] dissolved in the matrix, inducing finer dispersion of carbonitrides. Therefore, this model is proved to be effective in determining better chemical composition for high-performance steels, leading to possible reductions in the cost of production and improvements in the combined mechanical properties of the steels.

关键词： Microalloyed Carbonitrides thermodynamic model Dissolution

A thermodynamic model of solid solutions and its application in solid alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2022年第2期29卷 263-280页

作者： Zhen-nan Liu Chun-ling Yao Cong Liu Song-yuan Zhang Hui Huang Yong Cheng Faculty of Metallurgy and Mining Kunming Metallurgy CollegeKunming650033YunnanChina Kunming Key Laboratory of Comprehensive Utilization Resources of Rare and Precious Metals Kunming650033YunnanChina Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming650093YunnanChina

Based on the free volume theory, lattice model, the Scatchard–Hildebrand theory, novel expressions of configuration partition function and excessive Gibbs free energy and component activity coefficients of solid solutions were developed using configuration partition function and statistical thermodynamics of molecular interaction volume model (MIVM). Herein, the separation of the volume and energy parameters was achieved. The proposed model can reflect the contributions from both the molecular configuration micro-state number (entropy) and molecular interactions (enthalpy) toward excessive Gibbs free energy. The proposed equations are more consistent with the practical solid solutions. This model can use either the relevant binary infinite dilution activity coefficients or binary activity to describe and predict the thermodynamic properties of the multi-component solid solutions. Applications of the proposed model in some typical binary and ternary solid solution alloys revealed that the thermodynamic properties predicted by the proposed model were consistent with the experimental data and the proposed model was found to be superior to MIVM in terms of the prediction performance. Hence, it can be concluded that the proposed model exhibits good physical basis, applicability, stability and reliability.

关键词： thermodynamic model Molecular interaction volume model(MIVM) Solid solution thermodynamic property

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO_4-H_2O and NaF-H_2O binary solutions and NaClO_4-NaF-H_2O ternary solution

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 546-557页

作者： Xue-min Yang Wei-jie Zhao Han-jie Guo Qiang Zhang Jian Zhang State Key Lab of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Metallurgical Equipment Research ＆ Design Corporation Ltd. China Metallurgical Group Corporation Beijing 100029 China

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory （IMCT）. A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO4-NaF-H2O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H2O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law.

关键词： binary systems ternary systems thermodynamic model activity coefficient structural unit

A general thermodynamic model for the long-period stacking ordered phases in magnesium alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2021年第1期9卷 144-155页

作者： Kai Xu Shuhong Liu Keke Chang Yongpeng Liang Yong Du Zhanpeng Jin Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingboZhejiang 315201China Science and Technology on High Strength Structural Materials Laboratory Central South UniversityChangshaHunan 410083China School of Materials Science and Engineering Central South UniversityChangshaHunan 410083China

A thermodynamic model Mg x(Xs,Mg)6(Xl,Mg)8(Xs and Xl are elements smaller and larger than Mg)for long-period stacking ordered phases(LPSOs)was proposed based on two key factors:the Xs 6 Xl 8-type L12 clusters and the variation of chemical *** general,all available LPSOs can be described with this *** a representative system,Mg-Y-Zn with three LPSOs was investigated using the CALPHAD(calculation of phase diagram)approach aided with first-principles *** new three-phase equilibria were predicted and were validated by key *** model-based descriptions will be the basis for the research and development of magnesium alloys.

关键词： LPSOs thermodynamic model Formation enthalpy CALPHAD Solidification

A deoxidation thermodynamic model for 304 stainless steel considering multiple-components coupled reactions

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第1期31卷 74-91页

作者： Yan Yan Guang-hao Shang Li-ping Zhang Shao-ying Li Han-jie Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Henan Jinhui Stainless Steel Industry Group Co. Ltd.Xuchang461500HenanChina Changge Jinhui Recycling Metal R&D Co. Ltd.Xuchang461500HenanChina

A thermodynamic model for predicting the equilibrium oxygens of 304 stainless steel was developed based on the theory of slag-steel equilibrium,the law of mass conservation,and the ion and molecule coexistence *** the developed model,the Fe-Cr-Mn-Si-Al-S-O-melts reaction system and CaO-MgO-CaF_(2)-FeO-MnO-Al_(2)O_(3)-SiO_(2)-Cr2O_(3)slags were *** oxygen contents calculated by the model are in good agreement with experimental results and reference *** equilibrium oxygen contents in 304 stainless steel mainly decrease with increasing binary basicity(w(CaO)/w(SiO_(2)),where w(i)is the mass percentage of component i)and decreasing *** binary basicity at 2.0 while maintaining temperatures lower than 1823 K will keep the oxygen contents in the 304 stainless steel lower than 15×10^(-6).The equilibrium oxygen contents may also be decreased with increasing content of MgO in slags,which is more significant at lower binary ***,a small amount of FeO,MnO,and Al_(2)O_(3)(about 0-2.5 wt.%)in slags has little effect on equilibrium oxygen ***,it is found that the[C]-[O]reaction may occur during refining process but will not significantly affect the equilibrium oxygen contents.

关键词： Complex deoxidation thermodynamic model Ion and molecule coexistence theory 304 stainless steel Slag-steel reaction

A Coupled thermodynamic model for Prediction of Inclusions Precipitation during Solidification of Heat-resistant Steel Containing Cerium

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2015年第6期22卷 457-463页

作者： Yan-dong LI Cheng-jun LIU Chun-long LI Mao-fa JIANG Key Laboratory for Ecological Metallurgy of Multimetallic Minerals(Ministry of Education) Northeastern University Baotou Iron and Steel(Group)Company

A coupled thermodynamic model of inclusions precipitation both in liquid and solid phase and microseg- regation of solute elements during solidification of heat-resistant steel containing cerium was established. Then the model was validated by the SEM analysis of the industrial products. The type and amount of inclusions in solidifica- tion structure of 253MA heat-resistant steel were predicted by the model, and the valuable results for the inclusions controlling in 253MA steel were obtained. When the cerium addition increases, the types of inclusions transform from SiO2 and MnS to Ce2 O3 and Ce2O2 S in 253MA steel and the precipitation temperature of SiO2 and MnS decrea- ses. The inclusions CeS and CeN convert to Ce2 O3 and Ce2 O2 S as the oxygen content increases and Ce2 O3 and CeN convert to Ce2 O2 S, Ce3 S4, and MnS as the sulfur content increases. The formation temperature of SiO2 increases when the oxygen content increases and the MnS precipitation temperature increases when the sulfur content increa ses. There is only a small quantity of inclusions containing cerium in 253MA steel with high cleanliness, i. e. , low oxygen and sulfur contents. By contrast, a mass of SiO2 , MnS and Ce2 O2 S are formed in steel when the oxygen and sulfur contents are high enough. The condition that MnS precipitates in 253MA steel is 1.2wEo[O] ＋W[s]〉0. 01% and SiO2 precipitates when 2w[O] ＋wrs[S]〉0. 017% （W[S]0. 005%） and w[O]〉0. 006% （w[S]〉0. 005%）.

关键词： heat-resistant steel rare earth steel inclusion microsegregationl solidification thermodynamic model

thermodynamic model of Uranium and Arsenic Accumulation in Saline Lakes

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2014年第S1期88卷 135-136页

作者： Olga GASKOVA Vitaly ISUPOV Alexander VLADIMIROV Stepan SHVARTSEV Sobolev Institute of Geology and Mineralogy Siberian Branch of Russian Academy of Sciences Novosibirsk State University Institute of Solid State Chemistry and Mechanochemistry Siberian Branch of Russian Academy of Sciences Tomsk State University Tomsk Branch of the Trofimuk Institute of Oil and Gas Geology and Geophysics Siberian Branch of Russian Academy of Sciences

1 Introduction The attractiveness of Shaazgai-Nuur Soda Lake(pH9.2-9.4)as an alternative metal source is explained by the high concentration of dissolved uranium(~1 mg/l)due to the location of water drainage territory... 详细信息

关键词： saline lakes uranium arsenic sorption thermodynamic model calcite goethite.

thermodynamic model of lead oxide activity in PbO-CaO-SiO_2-FeO-Fe_2O_3 slag system

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2015年第5期25卷 1633-1639页

作者：汪金良温小椿张传福江西理工大学冶金与化学工程学院赣州341000 中南大学冶金与环境学院长沙410083

According to the ion and molecule coexistence theory, a thermodynamic model of lead oxide activity in PbO-CaO-SiO2-FeO-Fe2O3 slag system was established at the temperature of 1273-1733 K. The activities of Pb O in slag were calculated, and their equal activity curves were plotted. The influences of slag basicity Q, iron oxide rate R and temperature T on activity NPb O and activity coefficient γPbO were also investigated. Results show that the calculated values of γPb O are in good agreement with the reported experimental data, showing that the model can wholly embody the slag structural characteristics. NPbO departures positively from Raoult values, and increases with increasing Pb O content in slag but changes little with T. γPbO increases with increasing Q, and goes through the maximum with increasing R for basic slag（Q0.3）. Results can be applied to the thermodynamic research and operational optimization of modern lead smelting technologies.

关键词： ion and molecule coexistence theory thermodynamic model lead oxide activity

Quasi-thermodynamic model of MOVPE of InAlN

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2000年第8期21卷 729-734页

作者：陆大成段树坤中科院半导体所中科院半导体材料科学开放实验室北京 1 0 0 0 83 中科院半导体所集成光电子学联合国家重点实验室北京 1 0 0 0 83

A quasi\|thermodynamic model of MOVPE growth of In\- x Al 1- x N alloy with TMAl,TMIn and ammonia as sources has been *** this improved model,the effect of low decomposition rate of ammonia has been considered and the number of moles is used to express the mass conservation constraints of element N,H,Al and *** is assumed that the alloy is synthesized by the reactions between ammonia and group Ⅲ *** results show that it is more difficult to grow the In\-xAl 1-x N alloy,especially for the In\-xAl1-xN lattice matched the *** order to enhance the incorporation of indium into InAlN,we should use the lower growth temperature,optimized input Ⅴ/Ⅲ ratio and high nitrogen fraction in the carrier *** addition,the decomposed fraction of ammonia should be *** droplets would be deposited if the growth conditions have not been selected properly.

关键词： InAlN MOVPE thermodynamic model