材料期刊网

Formation and Thermal Stability of Large Precipitates and Oxides in Titanium and Niobium Microalloyed Steel

ZHUO Xiaojun , WOO Daehee , WANG Xinhua , LEE Haegeon

钢铁研究学报(英文版)

Ascast CC slabs of microalloyed steels are prone to surface and subsurface cracking. Precipitation phenomena initiated during solidification reduce ductility at high temperature. The unidirectional solidification unit is employed to simulate the solidification process during continuous casting. Precipitation behavior and thermal stability are systematically investigated. Samples of adding titanium and niobium to steels have been examined using field emission scanning electron microscope (FESEM), electron probe Xray microanalyzer (EPMA), and transmission electron microscope (TEM). It has been found that the addition of titanium and niobium to highstrength lowalloyed (HSLA) steel resulted in undesirable large precipitation in the steels, ie, precipitation of large precipitates with various morphologies. The composition of the large precipitates has been determined. The effect of cooling rate on (Ti,Nb)(C,N) precipitate formation is investigated. With increasing the cooling rate, titaniumrich (Ti,Nb)(C,N) precipitates are transformed to niobiumrich (Ti,Nb)(C,N) precipitates. The thermal stability of these large precipitates and oxides have been assessed by carrying out various heat treatments such as holding and quenching from temperature at 800 and 1 200 ℃. It has been found that titaniumrich (Ti,Nb)(C,N) precipitate is stable at about 1 200 ℃ and niobiumrich (Ti,Nb)(C,N) precipitate is stable at about 800 ℃. After reheating at 1 200 ℃ for 1 h, (Ca,Mn)S and TiN are precipitated from CaAl oxide. However, during reheating at 800 ℃ for 1 h, CaAlTi oxide in specimens was stable. The thermodynamic calculation of simulating the thermal process is employed. The calculation results are in good agreement with the experimental results.

关键词: carbonitride;microsegregation;dendritic region;unidirectional solidification;heat treatment;thermal stability

混合制冷剂相互作用系数的研究-Lee-Kesler-Pl(o)cker通用状态方程

吴献忠 , 李美玲

工程热物理学报

混合制冷剂的相互作用系数是制冷空调应用中建模和计算制冷剂热力性质所需的一个重要参数,本文利用大量的汽液相平衡实验数据结合LKP方程进行了热力学关联,提出了适合于计算HFCs混合制冷剂的相互作用系数的一种算法,求取的相互作用系数用于汽液相平衡和循环分析计算具有较高精度,与实验数据或其他热力模型计算结果吻合情况良好.

关键词: 混合制冷剂 , 相互作用系数 , LKP方程

改性腐植酸对稀土离子La3+,Ce3+吸附性能研究

杨睿琳 , 刘亚淳 , 朱科 , 黄皓 , 廖洋 , 赵仕林

中国稀土学报 doi:10.11785/S1000-4343.20160511

以腐植酸(HA)为原料,经两步酯化制备了改性腐植酸(HAE)吸附材料,用IR,SEM对HAE进行了表征,并考察了pH值、温度、离子浓度和时间等因素对其吸附行为的影响.实验结果表明:HAE对稀土离子的吸附在30 min左右即可达到平衡,pH值和离子浓度对h3+和Ce3+吸附量有较大影响,但温度对Ce3+吸附量的影响较小.La3+和Ce3+在pH =5.5,T=35℃条件下的饱和吸附容量分别为124.75和583.82mg·g-1,HAE材料对Ce3+的吸附量更大.HAE对La3+和Ce3+吸附过程都适于Freundlich模型,符合拟二级速率方程,重复使用4次,其吸附量变化不大.在模拟稀土废水中,经HAE材料吸附后稀土离子的浓度小于30 mg·L-1,达到国家稀土废水排放标准,该材料可用于处理低浓度的稀土废水.

关键词: 改性腐植酸 , La3 , Ce3+ , 吸附

锥形量热仪法研究抑烟填料对膨胀型防火涂料烟毒性能的影响

关迎东 , 李少香

涂料工业 doi:10.3969/j.issn.0253-4312.2010.12.001

利用锥形量热仪(CONE)实验获得的生烟速率(SPR)、生烟总量(TSP)以及CO生成速率(Pco)等参数,对抑烟填料硼酸锌(ZB)、阻燃抑烟剂(LEE)以及可膨胀石墨(EG)复配防火涂料的烟毒释放进行了对比研究.结果表明:抑烟填料硼酸锌(ZB)、阻燃抑烟剂(LEE)的加入明显降低了材料燃烧时的烟毒释放;物理膨胀填料EG与ZB、LEE体系复配能达到更好的阻燃抑烟协效作用,使烟毒参数进一步降低.

关键词: 抑烟填料 , 防火涂料 , 锥形量热仪 , 烟毒性

镀锌层出光及低铬钝化工艺

材料保护

工艺流程：镀锌-流动清水洗-出光（30-50mL／LHNO，，3-5mL／LHCl，室温，5-10s）-钝化（8-10g／LCrO3，0．8mL／LH2S04，2mL／LHN03，2-4mL／L醋酸（HAe），pH值为1．0-1．5，室温，8-12s）→一次回收→二次回收→两级逆流漂洗→热水洗→吹干→检验。

关键词: 钝化工艺 , 镀锌层 , 出光 , 低铬 , 二次回收 , 工艺流程 , pH值 , 水洗

EFFECTS OF THE PARABOLIC POTENTIAL AND CONFINED PHONONS ON THE POLARON IN A QUANTUM WIRE

Physical Review B

By using the Lee, Low, and Pines variational method, we have studied the electron-confined phonon, interaction within a rectangular quantum wire under an additional parabolic potential. Formulas for the polaron self-energy, the electron effective mass along the wire, and the ground-state energy are derived. Numerical calculations are performed for a typical GaAs quantum wire within the mesoscopic size using the idea of Fourier decomposition of the wave function. In comparison with previous calculations, our results show that the effect of phonon confinement always reduces the magnitude of the electron-phonon interaction and the associated physical quantities, whereas the additional parabolic potential tends to enhance not only this interaction but also the ground-state energy.

关键词: electron-gas;well;localization

基于边缘保持的SAR图像滤波算法研究

高珊 , 马艳会

液晶与显示 doi:10.3788/YJYXS20132802.0290

为了有效去除SAR图像中的相干斑噪声,同时很好地保留图像中的边缘细节,将双边滤波算法应用到SAR图像滤波,并使用ENL和EPI对其参数进行估计；经过参数估计的双边滤波算法作用于SAR图像后,很好地去除了斑点噪声且保留了边缘信息；实验结果表明,该算法的主观和客观数据都优于经典Lee滤波算法.

关键词: 相干斑去噪 , 双边滤波 , 边缘保持 , ENL , EPI

多轴疲劳破坏准则现状及评估

王英玉 , 姚卫星

材料工程 doi:10.3969/j.issn.1001-4381.2003.z1.009

简要回顾了材料多轴疲劳破坏准则,引用了5种材料在单轴、比例、纯扭和90°非比例加载情况的疲劳试验结果,对基于应力、应变和能量的有关多轴疲劳破坏准则进行了分析评估.分析结果表明:应力准则中Lee准则在各种材料、各种载荷情况下均可得到误差在5%以内的较好的预测结果,但是,Lee准则中含有物理意义不明确的材料常数,需要一定量的试验数据来拟合,从而限制了该准则的应用,比例加载下,Gough准则计算简单并可适用于大部分材料;应变准则中Kandil,Brown和Miller准则和Borodii和Strizhalo准则在各种材料及各种载荷情况下都能较好的预测疲劳寿命,但Borodii和Strizhalo准则需要大量的试验数据支持,从而限制了它的应用.

关键词: 多轴疲劳破坏准则 , 比例加载 , 非比例加载 , 评估

AZ31镁合金无铬阳极氧化新工艺

戎志丹 , 薛烽 , 孙扬善 , 肖盈盈 , 晏井利

材料保护 doi:10.3969/j.issn.1001-1560.2006.02.009

为了提高镁合金的耐腐蚀性能,采用直流阳极氧化工艺研究了一种新型无Cr环保型镁合金阳极氧化配方及工艺.溶液主要成分包含NaOH、Na3PO4、KF、铝盐和适量添加剂.结果表明,氧化膜主要由MgO和MgAl2O4组成;该环保型阳极氧化新工艺所获得的膜层的耐腐蚀性能等级为9级,优于传统的HAE工艺(8级),对AZ31镁合金能提供更有效的保护.

关键词: 阳极氧化 , 镁合金 , 环保 , 腐蚀防护

国产工业纯铁织构的磁转矩法研究

戴礼智 , 王建纲

金属学报

<正> 一、引言具有体心立方品格的α-Fe的织构早为许多研究者所注意,可是所用材料大多为低碳钢或Fe-Si合金。对于纯铁的数据比较少见.G.Kurdjumov和G.Sachs曾进行电解铁的轧制和再结晶织构的研究,压延率为98.5%,而没有叙及易磁向的再结晶织构.最近Haeβner和Weik用交叉轧制法研究化学方法制备的纯铁,经80%压延率在580℃熟炼150分后,得到易磁化取向.可是用普通方法轧制获得易磁向强构的资料就少见到.

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