材料期刊网

Improvement on Conventional Load Distribution Algorithm in Hot Tandem Mills

LI Haijun , XU Jianzhong , WANG Guodong , LIU Xianghua

钢铁研究学报(英文版)

Load distribution is a key technology in strip hot rolling process, which influences the coil′s microstructure and performance. Currently, NewtonRaphson algorithm is applied to load distribution of hot tandem mills in many hot rolling plants and has some serious defects such as having a strict restriction on initial iterative calculation value and requiring coefficient matrix of nonlinear equations to be nonsingular. To eliminate these defects and improve the online performance of the process control computer, Newton descendent numeric algorithm is introduced to this field to widen the initial value range and a new model named error conversion algorithm is put forth to deal with special conditions when the coefficient matrix is singular. Furthermore, considering the characteristics of load distribution, a condition of strip thickness distribution abnormality and corresponding solutions are provided which ensure that rolling parameters can be calculated normally. Simulation results show that the improved algorithm has overcome the defects of the NewtonRaphson algorithm and is suitable for online application.

关键词: load distribution;hot tandem mill;process control computer;NewtonRaphson algorithm

Analysis of Temperature Field and Thermal Crown of Roll During Hot Rolling by Simplified FEM

GUO Zhongfeng , LI Changsheng , XU Jianzhong , LIU Xianghua , WANG Guodong

钢铁研究学报(英文版)

Thermal crown of roll is an important factor, which affects strip profile. It is necessary to analyze the temperature field and thermal crown of roll for hot strip mill. A new simplified finite element method (FEM) was used to analyze the temperature field and thermal crown of roll, and corresponding models were built according to the practical boundary conditions. Transient roll temperature field and thermal crown were simulated by ANSYS FEM software with considering transient thermal contact and complex boundary condition. Temperature and thermal crown variations on roll surface nodes were obtained. The thermal crown results of roll obtained by FEM simulation were in good agreement with the measured data, indicating that simplified FEM models and results were correct.

关键词: temperature field;thermal crown;FEM;roll

Professor XU Zhong-yu and his research activities

新型炭材料

关键词:

Jian ZHANG/Langhong Lou

材料科学技术（英文）

关键词:

On the Indeterminacy in Hardness of Shape Memory Alloys

F.T.Cheng

材料科学技术（英文）

The present communication addresses an interesting problem related to the indeterminacy in hardness of superelastic NiTi reported by Xu et al. The origin of the indeterminacy is attributed to the inadequacy of the conventional Vickers hardness testing measurement which does not record elastic deformation, and thus the indeterminacy may be removed with suitable techniques. Concepts of hardness in relation to deformation are clarified. Recommendations for measuring the hardness of NiTi and other elastic-plastic materials are suggested, together with comments on the advantages and disadvantages of each of these methods.

关键词: Hardness , null , null , null , null , null

Broer-Kaup-Kupershmidt方程的新精确解

杨立娟 , 杨琼芬 , 杜先云

量子电子学报 doi:10.3969/j.issn.1007-5461.2012.02.003

CK方法是求解非线性发展方程的一种有效的直接方法.利用推广的CK方法,求得(2+1)维Broer-Kaup-Kupershmidt方程的Backlund公式,从而获得方程的大量新的精确解,推广了Xu和Zhang的结果.

关键词: 非线性发展方程 , Broer-Kaup-Kupershmidt方程 , 精确解 , CK方法 , Backlund变换

Thermodynamic analyses of strain-induced martensite transformation in Fe-7Mn-1.2C alloy

Jingpei XIE , Yaomin ZHU , Xiaoping WANG

材料科学技术（英文）

The M-s temperature, Delta G(gamma-->alpha), Delta G(gamma-->M) and mechanical energy under a non-severe impact loading in a medium manganese steel (Fe-7Mn-1.2C) have been calculated by means of Xu's Fe-X-C model. The relation between the yield strength of austenite and the driving force for martensite transformation has been established. It is proved that the martensite transformation can take place in a medium manganese steel (Fe-7Mn-1.2C alloy) under a non-severe impact loading.

关键词:

磷在12Cr1MoV钢中非平衡晶界偏聚动力学的实验研究

李莉 , 李庆芬 , 郑磊 , 徐庭栋 , 杜善义

钢铁研究学报

以工业用12Cr1MoV钢为研究对象,通过俄歇电子能谱分析方法(AES),对磷在恒温过程中的非平衡晶界偏聚浓度进行了测定.获得的磷在钢中的非平衡晶界偏聚动力学曲线直接验证了非平衡晶界偏聚动力学理论中的Xu-Song模型.

关键词: 晶界偏聚 , 临界时间 , 扩散 , 钢

DL-EPR法评价2205双相不锈钢晶间腐蚀敏感性

徐菊良 , 邓博 , 孙涛 , 李劲 , 蒋益明

金属学报 doi:10.3724/SP.J.1037.2009.00598

利用Thermo-Calc软件并结合金相显微镜,定性研究了2205双相不锈钢在800℃下敏化不同时间后的微观组织演变过程.通过研究扫描速率、介质成分、介质温度和试样表面状态优化了双环电化学动电位再活化法(DL-EPR),并用该优化方法研究了2205双相不锈钢晶间腐蚀敏感性.结果表明:DL-EPR法能定量评价σ相对2205双相不锈钢晶间腐蚀敏感性的影响,随敏化时间延长,σ相含量增多,晶jian 腐蚀敏感性也随之增加.腐蚀形貌的观测验证了这一规律,

关键词: 2205双相不锈钢 , DL-EPR , 晶间腐蚀敏感性 , σ相

磁致双折射和二向色性对磁性液体薄片的光透射率弛豫特性的影响

陆樟献 , 龚雁 , 王渊明 , 王正才 , 陈善飞

功能材料与器件学报 doi:10.3969/j.issn.1007-4252.2012.01.005

基于Xu等人的经典振荡磁偶极子模型和Matsumoto等人给出的双折射驰豫理论,研究了磁致双折射和二向色性对磁性液体薄片的光透射率弛豫特性的影响.理论推导了磁性液体的双折射和二向色性函数的偏振光透射率具体表达式,并进行了数值模拟计算.该问题的研究对磁性液体光学各向异性的深入认识以及相关磁性液体光学器件的应用具有一定的指导意义.

关键词: 物理光学 , 双折射驰豫 , 二向色性驰豫 , 磁性液体 , 磁偶极子