Xiaochun SHA
,
Chunli MO
,
Dianzhong LI
,
Yiyi LI
材料科学技术（英文）
Based on hot rolling production line of strip steel, the off-line in-house software, termed as ROLLAN (Rolling Analysis), is developed. The code is mainly used to predict the evolution of temperature, rolling force, fraction and grain size of recrystallization, fraction and grain size of phase transformation and final mechanical properties. Almost all the processing parameters affecting microstructure and mechanical properties in the schedule from reheating to the coiling process are considered in detail. Self-learning coefficient is adopted to adjust the deviation between predicted and measured temperatures, such as roughing exit temperature (RT2), finishing exit temperature (FT7) and coiling temperature (CT). Due to the application of low-speed-threading, increasing-speed-rolling and decreasing-speed-delivery process during finishing rolling and different cooling condition, after coiling the thermal-mechanical history of different position, along strip longitudinal direction is different resulting in inhomogeneous mechanical properties. So the segments are divided along longitudinal direction to identify the variation of microstructure and mechanical properties. An example of plain carbon strip steel Q235 with various thickness is used to compare the calculated mechanical properties with measured ones. For the specific grade of Q235 , the maximum deviation of tensile strength is less than 10.3 MPa, the yield strength is less than 13.2 MPa, and elongation is less than 1.99%. Further work will focus on the on-line application and consider the effect of macrosegregation and sulfur content of cast slab.
关键词:
Microstructural evolution
,
null
,
null
,
null
Yutuo ZHANG
,
Chunli MO
,
Dianzhong LI
,
Yiyi LI
材料科学技术（英文）
A model based on Avrami equation and Scheil’s additivity rule was proposed to simulate the phase transformation in plain carbon steels during continuous cooling in hot strip mill. In this model, a wide range of composition, cooling rate, primary austenite grain size and retained strain has been taken into account. It can be used to calculate the phase fraction transformed at different temperatures during continuous cooling. The phase equilibrium and transformation starting temperature can be determined by using Thermo-Calc and DICTRA. The simulated results containing the transformation at starting and finishing temperatures, Ae1 ,Ae3 and the maximum volume fraction for Q235B, were obtained. The calculated phase volume fractions are in good agreement with the experimental results.
关键词:
Phase transformation
,
null
,
null
陈松
,
胡昌义
,
郭俊梅
,
杨家明
稀有金属材料与工程
研究了Ir/Re喷管制备过程中的Ir/Mo互扩散问题.在电子探针测量的基础上,根据扩散理论和Ir-Mo相图数据,建立并推导Ir/Mo扩散模型和解.计算得到Ir3Mo相中的互扩散系数为:D=9.0×10-9exp(-1.46 eV/kT)(cm2/s),Ir基固溶体中的互扩散系数为:D=5.0×10-10exp(-1.1eV/kT)(cm2/s).确定喷管中Ir/Mo互扩散的特点,给出估算Ir3Mo相层厚的方法.确定Re在Ir3Mo相中的扩散主要是受Ir控制.
关键词:
Ir
,
Mo
,
Re
,
扩散
李云凯
,
王勇
,
李树奎
,
韩文波
复合材料学报
doi:10.3321/j.issn:1000-3851.2003.06.009
利用有限元分析方法,对PSZ/Mo功能梯度材料进行了优化设计,确定了最佳形状因子、层数和每一层的厚度.在此基础上,用热压烧结方法制备了六层结构的PSZ/Mo功能梯度材料.利用自制的FGM热性能测试仪,对制备的试样进行了热震性能实验,通过该实验条件下应力场和温度场的有限元计算,阐述了PSZ/Mo功能梯度材料优良抗热震性的原因.
关键词:
优化设计
,
有限元
,
PSZ/Mo功能梯度材料
LIANG Guoxian WANG Erde HUO Wencan Harbin Institute of Technology
,
Harbin
,
China Post Box 435
,
Harbin Institute of Technology
,
Harbin 150006
,
China
金属学报(英文版)
Ni_(100-x)Mo_x(x=20,30,38)alloys have been synthesized by mechanical alloying.The structure evolution of powders in mechanical alloying process has been monitored by X-ray diffraction,scanning electron microscopy and transmission electron microscopy analyses.The results show that the Ni_(62)Mo_(38)sample becomes partially amorphous after high energy ball milling,while the Ni_(80)Mo_(20)and Ni_(70)Mo_(30)become non-equilibrium nanocrystals.
关键词:
mechanical alloying
,
null
,
null
,
null
李雪
,
卢公昊
,
王淼
,
高田润
材料与冶金学报
doi:10.14186/j.cnki.1671-6620.2015.02.011
利用Al-Si混合粉末包覆金属Mo,并在Ar气氛围中,900℃进行高温扩散反应,在金属Mo表面制备Mo(Si,Al)2化合物层.在空气中12 00℃的条件下进行的高温氧化试验表明,化合物Mo(Si,Al)2具有优异的抗氧化性,样品外表面生成了致密的氧化铝层,从而阻止样品内部被进一步氧化.另外,氧化试验后在基体Mo和Mo (Si,Al)2层界面处还观察到Mo5(Si,Al)3层和Mo3 Al8层.
关键词:
金属Mo
,
Mo(Si,Al)2
,
粉末包覆法
,
高温抗氧化性
秦俊岭
,
易葵
,
邵建达
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2006.02.001
用磁控溅射法制备了Mo/Si薄膜,用AFM和XRD分别研究了Mo原子的溅射能量不同时,Mo/Si薄膜表面形貌和晶相的变化.通过比较发现,随着Mo原子溅射能量的增大,Mo/Si薄膜表面粗糙度增加,Mo和Si的特征X射线衍射峰也越来越强,并且Mo膜层和Si膜层之间生成了MoSi2.Mo原子的溅射能量是诱导非晶Si结晶和MoSi2生成的主要原因.
关键词:
Mo/Si
,
MoSi2
,
溅射能量
Journal of Magnetism and Magnetic Materials
The characterization and magnetic properties of YFe(12-x)Mo(x) (x=2.0, 2.5 and 3.0) with the ThMn(12)-type structure, and the magnetocaloric effect of YFe(9.5)Mo(2.5) were investigated. A directional growth was observed in YFe(10)Mo(2) alloy. A broad peak in the zero-field-cooling (ZFC) magnetization curve of the YFe(12-xx)Mo(x) compounds is ascribed to the existence of ferromagnetic clusters with different site moments and scattered orientations of the moments. The broad range of the peak is reduced with increasing Mo content. A weak peak is observed near 190 K in the ZFC curve of YFe(9)Mo(3), which is associated with the 8i sites being mostly occupied by Mo atoms. YFe(9.5)Mo(2.5) has a magnetic entropy change of -1.09 J/kg K for a field change of 5 T at 277 K. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Magnetic property;Magnetocaloric effect;YFe(12-x)Mo(x);transition;alloys
