LIN Jialiu ZHU Shigen YU Zhenzong Tsinghua University
,
Beijing
,
China
金属学报(英文版)
The stress-strain relation for cast low alloy carbon steel at solidification temperature has been examined by the authors' own desingned apparatus for rheological properties measurement.The rheology model,the stress-strain constitutive equation and the rheological parameters therefrom of the cast steel were proposed.Thus the theoretical basis and calcula- ting data for computerized s#nulation on the stress-strain relation and thermal cracking of the cast steel were suggested.
关键词:
rheological behaviour
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null
,
null
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null
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null
JIANG Laizhu CUI Kun Huazhong University of Science and Technology
,
Wuhan
,
China
金属学报(英文版)
Studies were made of the calculation of fractal dimension of transverse impact fracture sur- face,and of the correlation between impact toughness of steel and parameters of free-cutting phase by means of the developed fractal geometry model of crack propagation.It is believed that the area fraction,f,of free-cutting phase is negligibly influential to the longitudinal im- pact toughness,as f1 .While the aspect ratio,saying ratio of length to width,of free-cut. ting phase is inversely influential to the transverse impact toughness.This may .be the reason why the transverse impact toughness of free-cutting steel containing more rare earth contrast to sulphur is even higher than the low sulphur containing steel.
关键词:
fractal geometry
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null
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null
Liu Zhengyi Fu Jian Zhuang Yuzhi South China University of Technology
,
Guangzhou
,
China Correspondent:LIU Zhengyi professor
,
Dept.of Mechanical Engineering No.2
,
South China University of Technology
,
Guangzhou
,
China
金属学报(英文版)
The nature of“white layer”found in 55SiMnMo steel subjected to friction test has been stu- died using TEM,SEM,X-ray diffraction and EPMA techniques.It is shown that the struc- ture of the“white laver”on the rubbing surface is duplex,consisting of a special martensite and some austenite.This layer may be 25—50 μm thick.It is ultrafine,with grain diametric approximately 30 nm.Its micro-hardness may be as high as Hm 1500 and is capable of cut- ting glass.It has superb corrosion resistance and resists tempering.Its mierostructure and hardness undergo changes only when the steel is tempered above 500℃.
关键词:
friction
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null
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null
周镇
,
艾育华
,
孔文俊
工程热物理学报
本文利用双腔泄压式定压燃烧弹,研究了高压下典型IGCC合成气的层流火焰传播特性,得到了不同压力(0.1～1 MPa)和不同当量比下(0.6～3.0)合成气的层流火焰传播速度和Markstein长度.实验结果表明,层流火焰传播速度随当量比先增加后减少,随压力的增加而减小.Davis和Sun机理能较好地预测高压下合成气层流火焰的传播速度.Markstein长度随当量比的增加而增加,随压力的增加而减小.
关键词:
合成气
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球形火焰
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层流火焰传播速度
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Markstein长度
程杰锋
,
唐广波
,
刘正东
钢铁研究学报
选取了现有典型的C-Mn钢相变过程的物理冶金模型,包括5组孕育期模型、7组相变动力学方程模型、5组相变后铁素体晶粒尺寸模型.利用自行开发的组织性能预报系统软件模拟计算了在3组实际冷却工艺条件下各模型的奥氏体转变过程,并对各模型进行了评价.结果表明,对于所设定的成分和工艺条件,适用性较好的孕育期模型是Kwon所提出的模型;适用性较好的动力学方程模型是Liu、Donnay和Sun所提出的模型;适用性较好的铁索体晶粒尺寸模型是Hodgson所提出的模型.
关键词:
孕育期
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相变
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适用性分析
朱亮
,
肖毅
复合材料学报
为满足在工程应用中对建立拉压性能不同纤维增强复合材料的非线性本构理论的需要,考虑静水压影响的Drucker-Prager屈服准则与各向异性的Hill屈服准则相结合,提出了广义Hill屈服准则,并推广到Sun-Chen的单参数塑性模型中,建立了考虑拉压异性复合材料的非线性统一本构方程.实验验证结果表明,运用本文中所建立的本构模型能够很好地描述碳纤维/环氧(IM600/Q133)复合材料在偏轴拉伸和压缩载荷作用下的非线性响应.
关键词:
单向复合材料
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非线性响应
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不同屈服强度
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本构方程
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偏轴拉伸-压缩载荷
郝寅雷
无机材料学报
doi:10.3321/j.issn:1000-324X.2003.02.007
建立在均匀、无应力状态基础上的玻璃性质计算模型,在用于离子交换法制备的GRIN光学元件的折射率变化值(ΔN)计算时与实验结果有一定的偏差.本文对HSD(Higgins,Sun和Davis)模型和干福熹模型进行了比较,结果表明,干福熹模型用于低应力光学元件的计算时计算结果与实验值偏差较小,但对高应力GRIN光学元件的ΔN计算偏差很大;HSD模型在计算过程中分别考虑了玻璃组分的极化率因素和体积因素对其折射率的影响,在用于高应力GRIN光学元件ΔN计算时具有更强的适用性.
关键词:
梯度折射率
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离子交换
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玻璃
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模型
