锌湿法冶炼渣的自热焙烧无害化处理

针对湿法炼锌常压浸出渣和氧压浸出渣（均为危险废物）组成的高硫混合渣,系统考察了自热焙烧反应的各因素（温度、硫含量等）对渣中重金属固化效果的影响,并采用BCR连续提取法研究了焙烧前后渣中重金属的化学形态分布。结果表明,在焙烧温度1 000 ℃、混合物料硫质量分数20%、空气流速1.6 m3/h、焙烧时间7 h的条件下,渣中Zn、Pb、As、Cd等毒性浸出结果均可满足国家标准,渣率可降至约70%,焙烧热处理后渣中的Zn、Pb、As及Cd均以相对稳定的残渣态为主要化学形态,为锌湿法冶炼渣的低成本无害化与减量化处理提供了理论基础。     

旋转电极电渣重熔过程电极熔速的理论解析

摘要：旋转电极电渣重熔通过改变结晶器内熔体的流动和传热规律,增强了渣池与电极间的对流换热,在提高电极熔化速率和生产效率方面具有巨大潜力。提出了电渣重熔过程电极熔化速率的求解方法,并考虑了电极旋转时的强制对流,基于多物理场耦合模型预测了电极直径、转速对电极熔化速率的影响规律。结果表明,随着转速提高,金属液滴由从电极中心滴落向电极边缘滴落转变,高温区由渣池外侧向渣池中心移动。当转速从0增大至90r/min,55mm直径电极的熔化速率从7.90g/s增大至9.68g/s,对比固定电极,转速为90r/min时,生产效率最多提高了22.5%;进一步增大转速,电极熔化速率反而减小。存在一个最佳转速可使熔化速率达到最大,且该最佳转速随着电极直径的增大而减小。     

原位反应自发渗透法TiC／AZ91D镁基复合材料及AZ91D镁合金的拉伸变形与断裂行为

利用原位反应自发渗透技术合成了47．5％碳化钛TiC（体积分数，下同）增强AZ91D镁基复合材料，对比研究了该复合材料与铸态镁合金AZ91D基体的室温与高温拉伸变形行为，观察了拉伸断口微观组织形貌，并分析了这两种材料的断裂特征。结果表明，TiC／Mg复合材料具有良好的高温力学性能，在拉伸变形速率为0．001s^-1以及温度为723K，时其拉伸强度可达91．1MPa，而此时相同变形条件下的铸态AZ91D镁合金拉伸断裂强度只有41．1MPa，增幅达120％。而在室温下，镁基复合材料的拉伸断裂强度仅高出基体铸态镁合金23．4％。镁基复合材料的断裂应变较低，高低温时均表现为脆性断裂；而镁合金则由室温下的脆性断裂向高温下的韧性断裂过渡。     

CALCULATION OF TRANSFORMATION VOLUME FRACTION TO HQ590 HOT ROLLED STRIP STEEL DURING CONTINUOUS COOLING

On the basis of phase transformation kinetics, the transformation of γ→α,P,B have been investigated through considering the effect of deformation. The calculation methods of volume fraction have also been given. Comparing with common method, the simulated results are in more agreement with experiment results.     

Fe－Nb－C合金的高温内耗

测量了高纯Ｆｅ－Ｎｂ－Ｃ合金的４００－８５０℃内耗，发现一个峰温度随测量应变振幅变化的高温（６６６－７４０℃）磁机械滞后阻尼内耗峰。研究了峰的特征、出现、消失条件及升降温、频率、振幅、变形与退火等因素对峰的影响．提出了用内耗实验确定材料中阻碍铁磁畴壁Ｂａｒｋｈａｕｓｅｎ跳动应力的方法和合金中产生磁机械滞后阻尼－温度峰（Ｑ_ｍ~（－１）－Ｔ）的物理机制。     

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Mg-Li ALLOY WITH Ca ADDITION

Mg-9wt%Li-2wt%Zn alloy was prepared and studied in this article. The addition of Ca to the alloy from 0.1wt% to 1wt% can refine the α-Mg and the best effect of refinement occurs when Ca content is 0.4wt%-0.5wt%. The billets can be rolled to thin sheets at room temperature, from which it is obvious that the addition of Ca improves alloys ormalin. while it decreases with the excess addition of Ca. The results also show that the ultimate tensile strength （UTS） and yield strength （YS） of the alloy with lwt% Ca may rise by 28% and 25%, respectively, however, the elongation decreases. It is clarified that the adsorption of proper Ca on the grain boundaries refines α-Mg and improves the tensile properties, but the presence of excess Ca and stable Ca2Mg6Zn3phase worsens the elongation.     

Application of a time-dependent constitutive model to rheocast systems

A mathematical model has been developed to describe the velocity field in an agitated Al- 5Cu alloy in which B4C particles were suspended at different loading rates of up to 40 %. The material system was agitated by means of an electromagnetic rotary stirrer. The non- Newtonian behavior of the melt/solid slurry was allowed for using two models: the steady- state model of Joly and Flemings and the model of Brown, which takes account of time- dependent behavior. Calculations have shown that the two models behave similarly at high shear rates. In addition, if agitation was discontinued, very little time was required for the velocity (and hence the fluidity) of the slurry to decay.     

石墨化率不同的自焙炭块的热膨胀

采用精密垂直拉杆膨胀仪在１４～１０００℃范围内测量了具有不同石墨化率的自焙炭块的相对热伸长量，并由此获得了热线膨胀系数α。结果表明：石墨化率一定时，α值在较低温度下随温度升高而增加，在较高温度下，α值随温度变化不明显；恒温时，石墨化率越高，α值越低。讨论了单位热应力下的弹性模量概念     

Effects of Austempering after Hot Deformation on the Mechanical Properties of Hot Rolled Si-Mn TRIP Steel Sheets

Excellent mechanical properties are obtained by austempering after hot deformation without subsequent heat treatment in the present Si-Mn TRIP steel sheets. Isothermal holding time after finishing rolling has affected the mechanical properties of this steel. The results show that the sample exhibits a good combination of ultimate tensile strength and total elongation when it is held at the bainite transformation temperature after hot deformation. The stability of retained austenite increases with an increase of isothermal holding time, and a further increase in the holding duration results in a decrease of it. The tensile strength, total elongation and strength ductility reach the maximum values (774MPa, 33% and 25542MPa% respectively) for this sort of hot rolled Si-Mn TRIP steel using the optimal technology.     

铝液充型过程计算机可视化技术研究

采用透明的耐高温石英玻璃观察窗,观察和记录铝液充型过程的图像信息,分析铝液的充型过程;以图像处理技术和计算机技术为基础,通过充型过程铝液自由表面的边缘检测及提取技术,获取液体充型的自由表面曲线,定量分析铝液充型过程的自由表面变化;定量分析的试验结果表明,铝液实际充型过程自由表面的变化对浇注系统设计的合理性具有一定的指导意义.