光整对热镀锌IF钢板力学性能的影响

在生产DQ级以下的热镀锌机组上进行了Ti-IF钢热镀锌实验,研究了光整对Ti-IF钢热镀锌板力学性能的影响。实验结果表明：在正常情况下,热镀锌钢板其屈服强度在150MPa左右,r,n平均值分别为2．5和0．25。但是光整后,屈服强度明显提高,n值明显降低。根据实验结果,提出了根据用户的不同要求,采用不同的工艺路线来保证Ti-IF钢的力学性能。并且对热镀锌Ti-IF钢力学性能的控制问题进行了一些讨论。     

介孔CeO_2载体织构性质对Au-Pd催化剂性能的影响

以硝酸铈铵为前驱体,分别采用表面活性剂嵌段共聚物F127、十六烷基三甲基溴化铵(CTAB)和十六胺(HDA)合成介孔CeO2(m-CeO2)载体,研究了m-CeO2织构性质对Au-Pd双金属催化剂甲醇部分氧化制氢性能的影响,并运用HRTEM、XRD、TPR、H2-TPD、CO2-TPD和低温N2吸附等手段对Au-Pd双金属催化剂进行了表征。结果表明,HDA为表面活性剂合成的m-CeO2(H4)具有较大的比表面、孔容和孔径。H4负载的Au-Pd催化剂显示出较高的催化活性和氢气选择性。表征结果表明,Au-Pd/H4催化剂中贵金属的分散度较高、形成的Au、Pd活性中心较多,金属与载体的相互作用较强,表面的碱中心较多,产物H2较易脱附。     

Properties of the coke-pitch composition of the soderberg anode

Specimens from the zone of the coke-pitch composition (CPC) of ??dry?? and ??colloid?? Soderberg anodes with pitch contents of 28.2 and 24.0%, respectively, are sampled. The relative elongation coefficient and viscosity of the specimens are measured, and the granulometric composition of the coke charge is determined. It is noted that the properties associated with composition fluidity provide the uniform filling of the anode case even at a lowered pitch content. The redistribution of the coke particles in the CPC zone of the operating electrolyzer is characteristic of the dry anode during the sedimentation of the particles. No such phenomenon is noted for the CPC of the colloid anode. This excludes the possibility of stratification of the anode mass and forms more favorable environmental conditions for the electrolyzer operation.     

温度对铁基金属陶瓷性能的影响

本文以开发Fe-FeAl2O4金属陶瓷材料为目标,针对氧化物陶瓷的高强度、高硬度等性能和金属合金优良的导电性能和机械性能,采用粉末冶金的方法制备出以金属铁为基体,同时添加铁铝尖晶石为陶瓷相的金属陶瓷材料.本文探讨了铁基金属陶瓷材料的制备,研究了烧结温度对于特定比例下的金属陶瓷材料的性能的影响.对不同温度下的试样进行了导热系数、抗折强度的测试,采用SEM、XRD等方法研究试样微观结构与温度的关系.结果表明:在1 200℃温度下的试样,其各方面性能均优于其他温度,从而确定了最佳的烧结温度.     

钛石膏的性能研究

钛石膏为硫酸法钛白生产过程中的副产品,钛石膏大量堆积对环境造成污染,研究钛石膏的性能特点,对于选择合理的回收利用方案具有重要的指导意义。主要对钛石膏的物相组成、脱水温度、脱水时间和凝结特点进行试验研究。结果表明:钛石膏的主要物相为二水硫酸钙,少量物相为白云石,钛石膏脱除结晶水温度控制在200℃左右,脱除结晶水时间控制在50 min左右较适宜。添加柠檬酸作缓凝剂时,煅烧温度从120℃提高到200℃,钛石膏的凝结时间从1 800 s缩短为1 000 s,可以满足浇注成型的时间要求。     

Enhancement of the Cementitious Properties of Steelmaking Slag

Abstract

The overall objective of this work was to determine whether steel slag might be processed into a sufficiently cementitious material to allow it to be recycled as an additive to ordinary Portland cement clinker. Steel slag has limited cementitious properties due to both a lack of tricalcium silicate and the presence of wustite solid solutions as a predominant mineral phase. This work explores the effects of Fe oxidation state, overall composition, and cooling rate on the mineral structure, crystalline formation, and glass forming ability of several synthetic slags and one commercial BOF slag. XRD, SEM, and EDX analyses were performed on both slow cooled and quenched slags which had been oxidized. The granulated slag product was blended with Portland cement in varying ratios and hydrated to form cylindrical compression specimens. By controlling certain slag processing conditions, specifically the oxidation of bivalent xiron and the quenching rate of the molten slag, the cementitious nature of the material is enhanced. This allows the material to be blended with Portland cement (at additions of up to 20% by weight), without affecting the strength and performance of the material. © 1998 Published on behalf of Canadian Institute of Mining and Metallurgy by Elsevier Science Ltd. All rights reserved.

Résumé

L'objectif général de ce travail consistait à déterminer si on pouvait transformer le laitier de l'acier en un matériau ayant des propriétés ad é quates permettant de le recycler comme additif de clinker de ciment Portland ordinaire. Le laitier ctacier a des propriétés limité es comme ciment dll à la fois au manque de silicate tricalcique et à la présence de solutions solides de wustite dans la phse minerale pr é dominante. Ce travail explore les effets de l'état d'oxydation du Fe, de la composition générale et du taux de refroidissement su la structure minerale, sur la formation de cristaux et sur la capacité de formation de verre de plusieurs laitiers synthétiques et d'un laitier de fournaise basique a oxyg è ne. On a effectu é des analyses XRD, SEM et EDX, tant de laitiers refroidis lentement que de laitiers trempes, qui auparavant avaient ete oxydes. On a melange le produit de laitier granule avec du ciment Portland en diverses proportions et on l'a hydrate pour former des echantillons de compression cylindriques. En controlant certaines conditions de traitement du laitier, plus specifiquement l'oxydation du fer bivalent et le taux de trempe du laitier fondu, les propi étés-ciments de ce materiau sont ainsi ameliorées. Ceci permet de melanger le matériau avec du ciment Portland (additions jusqu' à 20% en poids), sans affecter la résistance ni la performance du matériau. © 1998 Published on behalf of Canadian Institute of Mining and Metallurgy by Elsevier Science Ltd. All rights reserved.     

Properties of the capillary structure of copper powder

Conclusions The properties of capillary structures of type PMS copper powder of different particle size composition obtained by sintering of freely poured material and by pressing with and without a poreforming material with subsequent sintering were investigated experimentally. It was shown that the capillary structures obtained by pressing with a pore-forming material possess uniformly high transport properties and a good quality of interparticle contacts.Translated from Poroshkovaya Metallurgiya, No. 8 (272), pp. 86–90, August, 1985.     

改善铝材卷取机卷筒性能的途径

简述了原有的卷取机卷筒的特点及不足,探讨了改善卷取机卷筒性能的一些途经。     

Review of the Magnetic Properties of Sintered Iron

Abstract

Throughout the past decade a number of new powder metallurgy processes have appeared which offer con siderable promise for superior aeroengine combustor, blade, and disc alloys. Furthermore, several features of these processes can be exploited for improved material utilization such that total manufacturing costs are contained to combat steep increases in basic alloying element prices. The processes include gas atomization of superalloy powder for critical rotating parts, rotating electrode atomization for titanium powder in similar components, controlled thermomechanical processing of attrited powders to produce oxide dispersion strengthened superalloy sheet and airfoil parts, and finally plasma-sprayed gas-atomized powder for advanced hot-section overlay and thermal barrier coatings. Considerable alloy and process development work has already been undertaken on all these systems by aeroengine material suppliers and advantages accruing in terms of superior properties and/or lower processing costs demonstrated at laboratory level and for some cases also in engine service. PM/0186     

Mg-Sc合金的热力学性质计算

根据Miedema模型,计算了Mg-Sc合金液态和固态时的生成焓.结合相关的热力学关系式,计算了该合金中Sc的活度曲线,并拟合了该合金的相互作用系数,发现本文所采用的Miedema模型和正规溶体模型对于Mg-Sc合金是适用的.     

Investigation of the Service Properties of the Electroslag Cast Metal

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Properties of the Hubert-Arable Adjusted Rand Index.

This article provides an investigation of cluster validation indices that relates 4 of the indices to the L. Hubert and P. Arable (1985) adjusted Rand index--the cluster validation measure of choice (G. W. Milligan & M. C. Cooper, 1986). It is shown how these other indices can be "roughly" transformed into the same scale as the adjusted Rand index. Furthermore, in-depth explanations are given of why classification rates should not be used in cluster validation research. The article concludes by summarizing several properties of the adjusted Rand index across many conditions and provides a method for testing the significance of observed adjusted Rand indices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

高斯粗糙表面辐射特性的数值研究

采用时域有限差分法和近场-远场变换对两种不同材料的一维微尺度高斯粗糙表面辐射特性进行了数值模拟,并将计算结果与其他方法进行了对比分析.研究结果表明,对于理想导电材料表面,随着均方根粗糙度的增加,其双向反射率的尖峰值逐步减小并最终消失;随着均方根粗糙度与表面关联距离之比的增加,向后反射变得愈加明显;相同表面轮廓特征条件下,理想导电材料与硅粗糙表面的双向反射率的总体趋势相同但后者要远小于前者;随着入射角度的增大,理想导电材料粗糙表面的双向反射变得趋于像镜面反射.