CAO Jin-rong
,
LIU Zheng-dong
,
CHENG Shi-chang
,
YANG Gang
,
XIE Jian-xin
钢铁研究学报(英文版)
Based on dislocation reaction theory and Avrami equation, a constitutive equation model was developed to describe dynamic recovery and dynamic recrystallization during hot deformation of T122 heat resistant steel, which have taken the effect of dynamic strain aging into account. Uniaxial hot compression test had been carried out over a wide range of strain rate (001 to 10 s-1) and temperature (900 to 1200 ℃) with the help of Gleeble 3500. Obtained experimental data was applied to determine the material parameters in proposed constitutive equations of T122 steel, by using the non-linear least square regress optimization method. The calculated constitutive equations are quantitatively in good agreement with experimentally measured curves and microstructure observation. It shows that propose constitutive equation T122 steel is able to be used to predict flow stress of T122 steel during hot deformation in austenite temperature scope.
关键词:
hot deformation
,
dislocation
,
constitutive equation
,
T122 heat resistant steel
YANG Gang
,
YANG Mu-xin
,
LIU Zheng-dong
,
WANG Chang
钢铁研究学报(英文版)
Commercial pure iron billets having diameter of 60 mm and length of 180 mm were subjected to equal channel angular pressing (ECAP) at 350 ℃ for 1 to 4 passes via route Bc. Microstructural evolutions on three planes (X, Y, Z planes) were characterized by optical microscopy and transmission electron microscopy (TEM). It was found that after four passes an ultrafine microstructure could be formed on the X plane, but a band structure remained on the Z plane. Accordingly, the mechanical properties exhibited apparent dependence on the orientations. The strength in the x and y directions was higher than that in the z direction. The microstructural refinement and mechanical properties were discussed in terms of experimental results.
关键词:
iron
,
ECAP
,
UFG
,
microstructure
,
mechanical property
YANG Gang
,
et al
钢铁研究学报(英文版)
The brittleness of M152 martensitic heat resistant steel due to slow cooling during quenching was experimentally investigated by means of mechanical property test, TEM and XRD analysis. The results showed that the nonreversal brittleness of M152 steel due to slow cooling during quenching was caused by the continuous precipitation of M23C6 along prior austenite grain boundaries and of M2C along prior residual austenite film. The residual austenite in the steel was unstable and may decompose due to the precipitation of second phase during the process of slow cooling after quenching. The low cooling rate in the temperature range from 820 to 660℃ has a strong effect on the impact toughness of the steel, the precipitation of second phase in the same temperature range results in nonreversal brittle.
关键词:
M152 martensitic steel;brittleness;M2C carbides;decomposition of residual austenite
Canying CAI
,
Qibin YANG
,
Hongrong LIU
材料科学技术(英文)
Assuming that the wave function , the Schrodinger equation can be written as . Neglecting the last two terms, an analytical expression of electron dynamical diffraction was derived by Qibin YANG et al. In this paper, the analytical expression is modified by further considering the second-order differential term . When the accelerating voltage is not very high, or the sample is not very thin, the reciprocal vector ɡ is large, the modification of the second-order differential is necessary; otherwise it can be neglected.
关键词:
Electron dynamical diffraction
,
null
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat(6)Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac(13)SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch&tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
颜慧成
,
郭征
,
张孟亭
,
张洪平
钢铁研究学报
引入变量m(冲量密度)和Yang-Mills型规范变换m=u+gradφ,将原始变量的N-S方程转化为规范-不变量形式,用自由质点法处理Voronoi元,对连铸结晶器弯月面处保护渣流动行为进行数学模拟.输出振动周期内的动态流场,然后结合一组试验数据进行计算,计算结果与实际情况相吻合,进而讨论了渣圈对液渣流动行为的影响,为研究结晶器弯月面处保护渣的行为和铸坯振痕的形成提供了一定的依据.
关键词:
连续铸钢
,
保护渣
,
流动行为
,
数学模拟
章明川
,
张楚
,
林郁郁
,
徐旭常
工程热物理学报
根据快速流化床的基本流动特性、A 型噎塞和 C 型噎塞的特征与定义,建立了一个统一,自恰的快速床模型一分相共存模型.模型以 A 型噎塞的修正Yang公式为‘本构方程',合理预报了快速床的最小固体流率Gsm,以及在固体流率不变的条件下降低操作气速时床层由A型噎塞向C型噎塞的连续过渡.模型中的稀相有效气流速度函数幂次n为可调参数,根据 C 型噎塞速度预报的Yousfi and Gau公式,初步确定模型参数n=4.
关键词:
快速流态化
,
噎塞速度
,
A 型噎塞
,
C 型噎塞
,
分相共存模型
章明川
,
张楚
工程热物理学报
通过介观机理解析及子模型的优化,对已建立的快速流化床动力学统一模型进行了改进.包括:1)模型参数n和气相速度有效系数F(β)的介观模型确定方法;2)A型噎塞Yang公式摩擦系数的实验再相关;3)Harris团聚物尺寸关联式的无因次重建;4)团聚物空隙率的预报及浓相模型修正.应用所建立的统一模型对垂直并流气-固系统的C型噎塞、快速床提升管上部稀相和下部浓相的固含率、以及向高密度快速床和浓相悬浮上升流的过渡等进行了综合性的预报,并得到文献中数百个不同实验结果很好的验证.
关键词:
快速流化床
,
介观机理解析
,
管壁摩擦系数
,
团聚物尺寸
,
实验验证
张志东
金属学报
doi:10.11900/0412.1961.2016.00336
本文首先回顾Ising 模型的研究历史, 包括Ising 模型简介、二维和三维Ising 模型的研究进展, 特别是二维Ising 模型的精确解. 然后介绍作者提出的有关三维Ising 模型的2 个猜想以及推定的精确解. 从拓扑、代数和几何的角度对三维Ising模型的数学结构进行了评述. 分析三维Ising 模型的转移矩阵、拓扑理论中的纽结变换、Yang-Baxter 方程和四面体方程之间的关系, 还介绍了三维Ising 模型中存在的非局域效应、与量子场论和规范理论的关系、权重因子的物理意义、无限大温度及附近的奇异性和拓扑相变. 指出一些近似计算方法(例如, 低温展开、高温展开、重整化群和Monte Carlo 模拟等)在研究三维Ising 模型时的局限性.
关键词:
Ising 模型
,
数学结构
,
精确解
,
拓扑性质
,
代数性质
,
几何性质