磁力旋流器磁系的磁场分析

设计了一种中心吸附铁化合物的磁力旋流器，利用试验和数值模拟的方法，对比分析了磁力旋流器磁场强度和分离性能。在试验中，简化了磁力旋流器磁系的结构，改变导磁铁片厚度、铁芯结构、磁系结构等参数，分析磁系对含铁化合物的吸附能力。利用数值模拟方法得到磁系的磁场强度，为分离能力预测提供依据。结果表明：磁场强度与导磁铁片的厚度成反比，随着导磁铁片厚度增大，磁场强度减小，磁力旋流器对铁化合物颗粒的吸附能力减弱，试验中导磁铁片的厚度为2mm时分离效果最好；铁棒铁芯磁系与铁管铁芯磁系相比具有更大的磁场强度；挤压式磁系与普通磁系相比具有更大的磁场强度。导磁铁片厚度的增大会使磁系端面漏磁量减少，铁芯侧面漏磁量增大；铁棒铁芯磁系的漏磁量相对较小，挤压式磁系的漏磁相对较小。     

交变磁场对水及生理盐水过冷过程的影响

为了研究磁场作用下水和生理盐水的过冷现象,搭建了可以实时测量记录冻结过程和磁场强度的试验台。20mL自来水或医用生理盐水被用作实验样本,磁场强度从0~64 G变化的50 Hz交变磁场被施加到样本上。实验结果发现交变磁场能够降低水和生理盐水的最低不结晶温度,水过冷度的增大与磁场强度能构成线性函数关系,生理盐水的过冷度增大与磁场强度能构成三次多项式函数关系;相同磁场强度下水的过冷度增加幅度大于生理盐水,在最大磁场强度(64 G)下水的过冷度增加了2.06℃而生理盐水过冷度增加了1.73℃;过冷度的增加导致过冷态时间延长,从而使得水体温度均匀性增加,推迟了成核时间。因此采用交变磁场能够增加水和生理盐水的过冷度,延长过冷时间,磁场的作用机理可能与水分子间的氢键形成和溶液中水合离子的洛伦兹力有关。     

脑蛋白水解新工艺的研究

以鲜猪脑制备脑蛋白粉，并利用微波化学和磁化学的技术促进其水解反应，研究了催化剂、催化剂用量、磁场强度、微波辐射时间对水解反应的影响。结果表明：用硫酸做催化剂比用盐酸好；磁场强度越强，水解效果越好，微波低能量多次辐射效果较好，低档火微波间歇辐射时间36min为较好。     

磁场作用下不同润湿性表面结霜实验研究

研究了在冷面温度T_w=-10℃和-30℃，环境相对湿度RH=60%和80%，3种润湿性表面在不同磁场强度下的结霜规律。通过可视化观测和图像二值化处理计算，分析了磁场强度和表面接触角对霜晶形态、水珠粒径、结晶时间、液滴和霜晶覆盖率、霜层厚度和密度的影响。结果表明：磁场作用下，疏水性表面水珠粒径减小40%左右，结晶时间延长500 s以上，凝结水珠分布更加稀疏；结霜厚度和密度随着磁场强度和接触角的增大而减小；随着冷面温度的降低和相对湿度的增大，表面特性和外加磁场对结霜过程的影响降低。     

医用核磁共振成像系统磁场强度示值误差的测量不确定度的评定

本文根据JJF(冀)3002-2018《医用磁共振成像系统校准规范》和JJF1059.1-2012《测量不确定度评定与表示》,介绍了核磁共振成像系统磁场强度示值误差的测量不确定度的评定方法,分析了各种不确定度的来源,给出了磁场强度示值误差的扩展不确定度及最后的分析结果。     

磁粉磁性测量中的几个问题

<正> 利用振动样品磁强计(VSM)测量磁粉的磁性,主要优点是:(1)外加磁场强度较大;(2)测量灵敏度较高;(3)能够测量样品的温度特性。实际上,影响VSM磁性测量结果的因素较多,必须逐一加以研究。本文仅探讨了仪器时间常数、测量时间、外加磁场强度和样品制备对于测量结果的某些影响。     

磁化Fe3O4吸附溶液中铬（VI）的研究

不同磁场强度下，Ｆｅ３Ｏ４磁性介质对含铬（ＶＩ）溶液的静态吸附实验结果表明：磁化的Ｆｅ３Ｏ４对铬（ＶＩ）的吸附能力比不磁化时强，磁化的Ｆｅ３Ｏ４的吸附平衡关系式可用同Ｌａｎｇｍｕｉｒ等温式类似的等温方程描述。磁场强度越大，吸附等温方程与实验值的相关性越好，磁性Ｆｅ３Ｏ４的吸附量随磁场强度增大而增大，它们之间的函数关系可用类似于Ｆｒｅｕｎｄｌｉｃｈ吸附数学模型描述。     

调整磁场强度分布提高靶材利用率

介绍了磁场强度在磁控溅射工艺中的作用 ,根据美国Airco公司镀膜生产线的实践经验 ,详细论述了如何通过调整靶材磁场强度 ,提高靶材的利用率。     

运用除铁器清除煤中覆铜雷管

介绍了除铁器的工作原理及煤中覆铜雷管的特征,理论上分析了利用除铁器吸出煤中覆铜雷管所需的磁场强度与煤流厚度之间的关系,计算得出,要想彻底清除煤流中覆铜雷管必须配备额定磁场强度不低于1500gs、表面磁场强度实测不低于3000gs的除铁器。     

磁场下电沉积制备Co-W合金镀层

在磁场下电沉积制备Co-W合金镀层,研究了磁场强度对镀层沉积速率、微观形貌、成分以及磁性能等的影响。结果表明:沉积速率随着磁场强度的增大而显著提高;洛伦兹力可以降低电极表面的浓差极化,避免氢气的析出,使镀层均匀、致密;随着磁场强度的增大,镀层的比饱和磁化强度逐渐增大,而矫顽力呈先增大后减小的趋势,当磁场强度为0.5T时,矫顽力最大。     

精炼钢包刚玉基耐火材料冲蚀的有限元分析

本文根据精炼钢包耐火材料的使用工艺条件,采用Johnson-cook模型,通过与实验值的对比,利用有限元模拟方法计算了刚玉基耐火材料在高温服役条件下的冲蚀率,研究了冲蚀角、冲蚀物速度、冲蚀物粒径和材料气孔率与冲蚀率之间的关系.结合耦合固液传热的精炼钢包钢液流场,对钢包精炼过程的冲蚀情况进行了分析和探讨.结果表明:采用Johnson-cook模型模拟高温条件下耐火材料以塑性切削为主的冲蚀,模型正确、参数合理;冲蚀角在15°～30°小角度范围内,冲蚀率较大,随后随着冲蚀角的增大而下降;冲蚀率与冲蚀物速度、冲蚀物尺寸、气孔率均呈现指数变化关系;精炼钢包刚玉基耐火材料主要是承受小角度切削冲蚀,服役过程中形成高熔点致密界面层能有效改善其抗冲蚀损毁.     

烘烤过程钢包包壁温度场的有限元研究

利用有限元法计算了烘烤过程钢包包壁温度场 ,研究了工作层、永久层和保温层厚度对钢包包壳温度的影响     

提高连铸钢包自动开浇率的研究

综述了影响钢包自动开浇率的各种因素 ,介绍了宝钢提高钢包自动开浇率的一些研究结果。重点研究了引流砂改进、钢水传搁时间及精炼方式对钢包自动开浇率的影响 ,通过采取一系列有效措施 ,宝钢连铸钢包自动开浇率达到了 98.5 %以上     

Indispensability and Vulnerability of Magnesia-carbon Bricks for Steelmaking Process

The manufacturing techniques of magnesia-carbon bricks in China have been documented from raw materials,production(process and facilities)to performance and wear issues in the ladle.Magnesia-carbon bricks made of ordinary fused magnesia is the prevailing material used in the slagline of the ladle,but its service life is substantially lower than the bricks based on large-periclase-crystal fused magnesia.In two types of fused magnesia,the average values of periclase crystal size are in double for their difference.It is suggested that large-periclase-crystal fused magnesia should be used for manufacturing magnesia-carbon bricks for the slagline of the ladle by abandoning ordinary fused magnesia,in order to have a prolonged service life,increase the availability of the ladle and reduce the number of downtimes of the ladle.Free phenol in resin produced in China should be as low as that of resin made in Europe,to improve production environment and reduce smoke emission during the ladle preheating.There are large spaces to promote the productivity of magnesia-carbon bricks in China,with high intensity mixers and hydraulic presses.Expansion controlled magnesia-carbon bricks in the ladle depend on the optimized combination of sintered magnesia,Carbores and antioxidants as the matrix,to minimize the premature wear of vertical cracks and joint opening formed in the ladle lining.     

宝钢转炉钢包用耐火材料的现状及发展趋势

综述了宝钢转炉钢包用耐火材料的变化过程及使用现状 ,重点介绍了近年来宝钢在钢包耐火材料使用上的一些技术进步 ,提出了存在的问题及对策 ,展望了今后宝钢转炉钢包的发展方向。     

宝钢300t钢包粘渣的原因及对策

介绍了宝钢３００ ｔ 钢包在使用中粘渣的情况，分析了钢包粘渣的原因。特别针对近来钢包超重非常严重的状况，在调查研究的基础上提出了一些措施，但从长远来看，要解决此问题必须根据宝钢的使用条件深入研究渣和耐火材料的反应机理，使耐火材料更好地适应炼钢生产的要求。     

Testing ladle brick made by various factories

Conclusions The resistance of linings in steel-casting ladles depends on the working conditions and the construction of the lining, the quality of the brick laying during repairs of the working layer, and the resistance of the ladle brick. The greatest effect on the wear of the lining in ladles is exerted by the following working conditions: chemical composition of the slag, temperature of the metal being cast, the dwell time of metal and slag in the ladle during one casting, the height of the slag layer in the ladle, the thickness of the lining in each belt of the structure. The quality of the structure in the ladles is mainly determined by the size of the joints, the care with which they are filled with mortar, uniformity of drying and warming-up of the ladles before filling them with metal.The resistance of the ladle brick depends mainly on the apparent porosity and nature of the pores and the concentration of fluxes and mullite in the brick.The highest resistance in service was shown by Zaporozh'e ladle brick made from Polozhe kaolin and having the lowest apparent porosity. The concentration of iron oxides in the brick was moderate, and on average equalled 1.39%.In terms of falling resistance the ladle brick of the remaining concerns can be placed in the following order: Chasov-Yar, Semiluks, Bogdanovich, Magnitogorsk, and Borovich.In order to increase the resistance of steel casting ladle linings it is necessary to increase the resistance of the ladle brick by reducing the apparent porosity, using raw materials with low concentrations of fluxes and improving the firing in order to obtain the maximum conditions of the ladle, reducing to a minimum the quantity of slag and reducing the casting time; to use a more rational thickness for laying the ladles over the courses, taking into account better use of their capacity.Translated from Ogneupory, No.5, pp. 27–32, May, 1970.     

RH真空处理过程中钢中氧含量预测模型

针对３００ｔ钢包ＲＨ真空处理低碳铝镇静钢的多次试验数据，建立了ＲＨ处理过程中钢中氧含量的定量预测模型，得到了钢中氧含量的预测公式模型综合考虑了纯脱气时间、真空室吹氩流量、钢水环流量、钢包渣中ＦｅＯ＋ＭｎＯ含量、钢包内衬材质等因素的影响，并对改进ＲＨ操作进行了讨论     

300t精炼钢包温度场和应力场的有限元分析

在目前所用材质体系和砌筑结构的基础上,对精炼过程中的300 t精炼钢包剪切应力场、温度场和热应力场以及膨胀缝的最大接触应力进行了有限元研究.结果表明:在LF精炼过程中,渣线处的内衬砖最容易受冲刷和热应力的作用而损毁,需在保证良好抗渣性能的同时采用热膨胀系数低、抗冲刷性好的耐火内衬砖;膨胀缝的最大接触应力与膨胀缝的大小呈线性反比关系,以保持在0.8～1.8 mm之间为宜.     

Cementitious properties of ladle slag fines under autoclave curing conditions

Ladle slag fines consist mainly of γ-C₂S, which does not show cementitious property in water, but can exhibit significant cementitious property in the presence of alkaline activators at room temperatures. This study deals with the hydraulic reactivity of ladle slag fines under autoclaving conditions. The results indicate that ladle slag fines cannot be used as cementing material alone because of the presence of free lime in ladle slag. The combination of a ladle slag fine and a siliceous material, such as silica flour (ground quartz), can eliminate the soundness problem and give very high strength. The introduction of a small amount of Portland cement or hydrated lime into ladle slag fine-silica flour system can increase strength significantly. Lime is more effective than Portland cement due to the presence of Al in Portland cement. The autoclaving temperature should be higher than 175 °C and the time for constant temperature does not need to be more than 4 h to achieve satisfactory strength. Finally, seven batches of experiments are designed to plot isostrength contours for ladle slag fine-cement-silica flour and ladle slag fine-hydrated lime-silica flour ternary systems.