The valence electron structure (VES) in compound layer of steel plasma-nitrided at 560°C with rare earth (RE) addition was calculated based on the empirical electron theory (EET) of solids and molecules and BLD m...The valence electron structure (VES) in compound layer of steel plasma-nitrided at 560°C with rare earth (RE) addition was calculated based on the empirical electron theory (EET) of solids and molecules and BLD method. The results show that the presence of RE atoms diffused into surface layer leads to an increase of phase structure factor, which explains the catalyzing and micro-alloying effects of RE.展开更多
Based on S. H. Yu’s empirical electron theory of solids and molecules, the valence electron structure of austenite in low alloy ultrahigh-strength steels, 30CrMnSiNi<sub>2</sub>A and 40 CrMnSiMoVA is esta...Based on S. H. Yu’s empirical electron theory of solids and molecules, the valence electron structure of austenite in low alloy ultrahigh-strength steels, 30CrMnSiNi<sub>2</sub>A and 40 CrMnSiMoVA is established. The behavior of various main-added elements in the kinetics of phase transformation is discussed on the basis of C-Me segregation caused by the valence electron structure, The influence of alloying elements on the structure and morphology of transformed products is discussed from the viewpoint of interaction between the driving force of phase transformation and segregating force. Then on the basis of the valence electron structure of the alloy, the composition design of ultrahlgh-strength steels is discussed.展开更多
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 t...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.展开更多
Theoretical study on the short-range ordered segregation of alloying elements dissolving in solid solution in C-Me form has made some progress in recent years, which has already been verified by the electron probe, th...Theoretical study on the short-range ordered segregation of alloying elements dissolving in solid solution in C-Me form has made some progress in recent years, which has already been verified by the electron probe, the Mssbauer spectroscopy technique, and so on. Based on the empirical electron theory of solids and molecules (EET), and展开更多
Ⅰ. THE VALENCE ELECTRON STRUCTURES OF MARTENSITE IN LOW ALLOY ULTRAHIGH-STRENGTH STEELS AND THE SEGREGATION OF C-ME IN MARTENSITEThe valence electron structures ofmartensite in 30CrMnSiNi<sub>2</sub>A and...Ⅰ. THE VALENCE ELECTRON STRUCTURES OF MARTENSITE IN LOW ALLOY ULTRAHIGH-STRENGTH STEELS AND THE SEGREGATION OF C-ME IN MARTENSITEThe valence electron structures ofmartensite in 30CrMnSiNi<sub>2</sub>A and Gc-4 steels can be established based on Refs. [1—3]. To be brief, only σ, n<sub>A</sub> and n<sub>c</sub><sup>D</sup> are listed in Table 1, which are the values of electron structures of martensite in 30CrMnSi<sub>2</sub>A and Gc-4 steels.展开更多
Based on R. H. Yu’s empirical electron theory of solids and molecules, the bond length difference (BLD) analysis has been carried out on 40CrNiMo austenite structure. The valence electron structure of the austenite h...Based on R. H. Yu’s empirical electron theory of solids and molecules, the bond length difference (BLD) analysis has been carried out on 40CrNiMo austenite structure. The valence electron structure of the austenite has been established on the basis of atomic hybridization state, atomic magnetic moment, experimental bond length, etc. ; the short range segregation of C-Cr, C-Ni, C-Mo in austenite has been ratiocinated from microscopic non-homogenerous theory of solid solusion; and the effects of C-Cr, C-Ni, C-Mo segrefation on transformation product have been proved by electronic microscopic analysis and energy spectroscopic analysis. Therefore, the formation of isothermal transformation kinetic curve of 40Cr-NiMo can be traced back to the valence electron structure of alloy phase.展开更多
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 ...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 nA, FcD, the weighting of each unit cell and the degree of undercooling on phase transition of the austenite, 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.展开更多
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...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).展开更多
为了揭示高铬铸铁组织的微观本质并利用其分析结果预测合金的淬硬性,利用余瑞璜的固体与分子经验电子理论(EET)和Fe C Cr三元系平衡相图对Fe C Cr三元系高铬铸铁合金奥氏体的价电子结构进行了分析。结果表明,在工业应用的成分范围内C C...为了揭示高铬铸铁组织的微观本质并利用其分析结果预测合金的淬硬性,利用余瑞璜的固体与分子经验电子理论(EET)和Fe C Cr三元系平衡相图对Fe C Cr三元系高铬铸铁合金奥氏体的价电子结构进行了分析。结果表明,在工业应用的成分范围内C Cr键是合金奥氏体所有键中的最强键,形成C Cr偏聚单元。wCr/wC≥6时,含C Cr结构单元的权重会大大提高,促进了奥氏体的陈留,可以获得奥氏体基体组织。当wCr/wC=5.5～6.5时,Fe C Cr三元系高铬铸铁可获得最佳的淬硬性。展开更多
基金support from the key laboratory foundation of precision hot forming for national defense science and technology.
文摘The valence electron structure (VES) in compound layer of steel plasma-nitrided at 560°C with rare earth (RE) addition was calculated based on the empirical electron theory (EET) of solids and molecules and BLD method. The results show that the presence of RE atoms diffused into surface layer leads to an increase of phase structure factor, which explains the catalyzing and micro-alloying effects of RE.
文摘Based on S. H. Yu’s empirical electron theory of solids and molecules, the valence electron structure of austenite in low alloy ultrahigh-strength steels, 30CrMnSiNi<sub>2</sub>A and 40 CrMnSiMoVA is established. The behavior of various main-added elements in the kinetics of phase transformation is discussed on the basis of C-Me segregation caused by the valence electron structure, The influence of alloying elements on the structure and morphology of transformed products is discussed from the viewpoint of interaction between the driving force of phase transformation and segregating force. Then on the basis of the valence electron structure of the alloy, the composition design of ultrahlgh-strength steels is discussed.
基金Funded by the Science and Technology Foundation of Retuned Students Studying Abroad of Shanxi Province of China(No. 1995-26)
文摘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.
文摘Theoretical study on the short-range ordered segregation of alloying elements dissolving in solid solution in C-Me form has made some progress in recent years, which has already been verified by the electron probe, the Mssbauer spectroscopy technique, and so on. Based on the empirical electron theory of solids and molecules (EET), and
文摘Ⅰ. THE VALENCE ELECTRON STRUCTURES OF MARTENSITE IN LOW ALLOY ULTRAHIGH-STRENGTH STEELS AND THE SEGREGATION OF C-ME IN MARTENSITEThe valence electron structures ofmartensite in 30CrMnSiNi<sub>2</sub>A and Gc-4 steels can be established based on Refs. [1—3]. To be brief, only σ, n<sub>A</sub> and n<sub>c</sub><sup>D</sup> are listed in Table 1, which are the values of electron structures of martensite in 30CrMnSi<sub>2</sub>A and Gc-4 steels.
文摘Based on R. H. Yu’s empirical electron theory of solids and molecules, the bond length difference (BLD) analysis has been carried out on 40CrNiMo austenite structure. The valence electron structure of the austenite has been established on the basis of atomic hybridization state, atomic magnetic moment, experimental bond length, etc. ; the short range segregation of C-Cr, C-Ni, C-Mo in austenite has been ratiocinated from microscopic non-homogenerous theory of solid solusion; and the effects of C-Cr, C-Ni, C-Mo segrefation on transformation product have been proved by electronic microscopic analysis and energy spectroscopic analysis. Therefore, the formation of isothermal transformation kinetic curve of 40Cr-NiMo can be traced back to the valence electron structure of alloy phase.
文摘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 nA, FcD, the weighting of each unit cell and the degree of undercooling on phase transition of the austenite, 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.
文摘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).
文摘为了揭示高铬铸铁组织的微观本质并利用其分析结果预测合金的淬硬性,利用余瑞璜的固体与分子经验电子理论(EET)和Fe C Cr三元系平衡相图对Fe C Cr三元系高铬铸铁合金奥氏体的价电子结构进行了分析。结果表明,在工业应用的成分范围内C Cr键是合金奥氏体所有键中的最强键,形成C Cr偏聚单元。wCr/wC≥6时,含C Cr结构单元的权重会大大提高,促进了奥氏体的陈留,可以获得奥氏体基体组织。当wCr/wC=5.5～6.5时,Fe C Cr三元系高铬铸铁可获得最佳的淬硬性。
