半固态成形用电磁搅拌器内部磁场的三维表征研究

利用三维数字化测磁手段对半固态浆料制备用电磁搅拌器的磁场进行测量。结果发现,电磁搅拌器内部磁感应强度在100mT附近,磁感应强度沿搅拌器轴向及径向分布均匀,不同电磁搅拌电压、频率组合产生的搅拌磁场强度变化明显。     

电磁搅拌电流对连铸紫铜管组织和性能的影响

水平连铸管材常产生晶粒粗大、壁厚不均匀、表面裂纹、气孔等缺陷。为改善连铸铜管的质量,在水平连铸装置中配置了电磁搅拌器,并在连铸外径80 mm、壁厚12 mm的紫铜管的过程中向电磁搅拌器通入80～190 A工频电流对熔体进行电磁搅拌。检验了铜管的组织、表面质量、壁厚均匀性和电导率,并与未施加电磁搅拌连铸的紫铜管进行了比较。结果表明:由于施加了电磁搅拌,紫铜管中的气孔等缺陷明显减少从而致密度提高,表面裂纹消除,壁厚差不超过±0.5 mm。随着电磁搅拌电流的提高,紫铜管组织由粗大的柱状晶转变为细小的等轴晶。未施加电磁搅拌连铸的紫铜管氧含量为0.029 1‰,而施加由190 A电流产生的电磁搅拌连铸的管坯氧含量下降到了0.006 0‰,电导率则从98.214%IACS提高到了100.72%IACS。     

结晶器电磁搅拌技术的应用实践

介绍了连铸电磁搅拌器的分类及其对铸坯质量的影响,以及根据不同钢种的冶金质量要求合理选择电磁搅拌器的原则,分析了马钢方坯、圆坯连铸应用结晶器电磁搅拌的冶金效果,并对存在的问题提出了相应的改进建议.     

电磁搅拌技术在铸造铝合金熔炼中的应用

把电磁搅拌枝术应用到铝合金熔炼过程中，显示了该技术的优良特性。熔炼时间缩短了，熔体温度下降了近５０℃，吨纯铝节省电能２００ｋＷｈ，且化学成分稳定、均匀，产能、质量都获得提高。操作者的劳动强度减轻。电磁搅拌器在使用过程中基本上不用维修，操作简单，运行令人满意。     

ABB电磁搅拌器国产化研究及改进

针对湖南华菱湘潭钢铁集团有限公司引进ABB大方坯异形电磁搅拌器在使用过程中出现接头渗漏、绝缘下降、寿命短等问题,开展了ABB电磁搅拌器国产化研究及改进设计。介绍了ABB电磁搅拌器的结构、特点和不足,简述了其磁感应强度分布;为保证改进电磁搅拌器的磁场强度,设计时使用了ANSYS有限元分析软件对磁感应强度理论数据进行了模拟,能够满足工艺需求。     

中国连铸电磁搅拌技术已进入世界前列

简要回顾中国连续铸钢用电磁搅拌技术发展历程,以方坯连铸凝固末端电磁搅拌器维修、板坯连铸用高推力辊式电磁搅拌器和多极宽板坯结晶器电磁搅拌器的创新研发等3个实例佐证中国连铸用电磁搅拌技术已进入世界前列。     

辊式电磁搅拌器在包钢电工钢上的应用

通过辊式电磁搅拌器的实际应用,以及硫印、酸洗等方法研究了辊式电磁搅器对电工钢铸坯质量的影响。通过理论分析和试验结果表明,电工钢施加辊式电磁搅拌器后,铸坯的等轴晶率有明显的提高,可以达50%以上,夹杂物的分布有所改善,电工钢的成品质量得到很大的提高。     

电磁搅拌器对提高铝熔体质量的作用

电磁搅拌器已成为美国、欧洲和日本等国家和地区铝熔化炉和铝保温炉的标准配置件。电磁搅拌技术对提高铝合金熔体均匀化、提高熔体质量、缩短铝熔炼时间、节约能源、减少铝氧化夹渣等方面有良好的作用     

电磁搅拌对AlSi7Mg合金显微组织的影响

采用自行开发的电磁搅拌器,研究了多种不同电磁搅拌方式,在不同工艺条件下,单独施加或复合施加对AlSi7Mg合金微观组织的影响.试验结果表明：单一施加旋转感应电磁搅拌时,浆料径向组织很不均匀;单一施加无芯感应电磁搅拌,当搅拌电流较小时,径向组织也不均匀,增大电流浆料质量有明显改善;采用（旋转感应＋无芯感应）复合电磁场进行复合电磁搅拌时,可在电流较小时获得满意的浆料质量.     

舞钢板坯连铸机二冷区电磁搅拌器的参数及其性能

阐述了舞钢板坯连铸机二冷区选用双边行波磁场搅拌器的原理, 给出采用解析法导出的该类型电磁搅拌器中心电磁推力的表达式以及二冷区用电磁搅拌器的电磁参数和冷却系统参数的计算结果。冷态性能测试结果表明, 舞钢板坯连铸机二冷区用电磁搅拌器的研制非常成功     

Research on investment casting of TiAl alloy agitator treated by HIP and HT

Using TiAl alloy to substitute superalloy is a hot topic in aeroengine industry because of its low density, high elevated temperature strength, and anti-oxidization ability. In this research, Ti-47.5AL-2Cr-2Nb-0.2B alloy was used as the test material. By applying a combination process of ceramic shell mold and core making, vacuum arc melting and centrifugal pouring, and heat isostatic pressing (HIP) and heat treatment (HT) etc., the TiAl vortex agitator casting for aeroengine was successfully made. This paper introduced key techniques in making the TiAl vortex agitator with investment casting process, provided some experimental results including mechanical properties and machinability, and explained some concerns that could affect applications of TiAl castings.     

铂铑包覆钼合金搅拌器的研制

介绍了铂铑包覆钼合金搅拌器的结构与技术要求,以及搅拌器的制作与使用效果。研制结果表明,国产搅拌器达到了日本同类产品的水平。     

行星搅拌器数值模拟与桨型分析

对用于高黏度浆料搅拌的某型号三桨行星搅拌器进行数值模拟和桨型研究,通过螺距的变化改变桨型得到另外2个方案。对3个方案分别进行了仿真模拟,从流场分布、速度分布、扭矩、功率等维度进行对比。结果表明:增大螺距,桨型更接近框式,搅拌器排出和切向循环能力增强,轴向循环能力减弱,搅拌扭矩和功率增大;减小螺距,桨型更接近螺带式,搅拌器轴向循环能力增强,排出和切向循环能力减弱,搅拌扭矩和功率减小。适中的螺距和桨型,有利于提升行星搅拌器的复合搅拌效果。     

淬火冷却设备的选择

主要阐述淬火冷却系统的设计原则、搅拌器选择、淬火介质控制、自动灭火和油烟净化等内容.借此希望机械行业"重冷轻热"、热处理"重热轻冷"的现象尽快改变,扭转观念,重视热处理,重视淬火冷却.     

混凝土搅拌运输车副车架的受力分析及结构优化

副车架是搅拌车的重要部件，其塑性变形及断裂是常见的失效形式。根据副车架的实际受力形式，设计出了一种新的结构，并采用美国ZonicBook／618E便携式实时状态监测分析系统和TT9000扭矩遥测系统对副车架在实际使用过程中的受力状态做了实时监测，验证了设计的正确性和可靠性。     

流速对船舶海底阀箱5083-H116铝合金电化学行为的影响

研究流速对铝制船舶的海底阀箱材料5083-H116铝合金电化学行为的影响。为检测电化学特性和流速对其性能的影响,实验在静态和通过搅拌仪产生的4个不同流速下进行,并使用超声波振荡器利用压电效应进行空化实验。结果表明,合金在施加流速后其腐蚀电流密度和损害程度较在静态环境下增加,更易于发生腐蚀。     

Walzplattierung WStE 355/NiMo 28 (Alloy B-2): Eine preisgünstige Werkstoffkombination für die Chemietechnik

Roll cladding WStE 355/NiMo 28 (Alloy B-2): A low cost alternative material combination for the chemical industry This paper describes the manufacture of rolled clad plates – base metal fine grain structural steel similar to WStE 355, cladding metal nickel alloy NiMo 28. From one plate, subsequently a semi-elliptical head was fabricated. Difficulties had so far been encountered in the manufacture of such roll claddings: Due to heat input during rolling precipitations had occurred in the cladding metal. In order to achieve satisfactory corrosion resistance of the nickel alloy, solution annealing was necessary. This heat treatment resulted in the formation of coarse grain in the base metal, adversely affecting the mechanical properties. A modification of the chemical composition of the base metal and a heat treatment adjusted to the sandwich material made it possible to produce clad plates with fully satisfactory properties. The mechanical and technological properties of the base metal met the standard requirements for fine grain structural steel WStE 355. The corrosion resistance characteristics of the cladding metal were practically unchanged in the solution-annealed condition as compared to the nickel alloy. Welded joints were made to test the weldability of the sandwich material. Testing of the welded joints has yielded satisfactory results. A comparison of manufacturing costs of an agitator tank – capacity 6.3 m³, operating temperature 300°C, working pressure 2.5 bar (absolute value) – showed that total costs were reduced by 15%, if the tank was made of clad plate as compared with a tank made of Alloy B-2 solid plate.     

硝盐等温淬火设备的设计与发展

硝盐淬火与传统油淬火相比有淬冷温度高,工件变形小、硝盐不易老化、安全性高,并可回收利用等特点.本文介绍硝盐淬火设备的构成和类型,重点阐述硝盐淬火槽结构和设计,涉及槽体、盐搅拌器、导流装置、淬火升降台、冷却等的设计要点.简述了等温槽、盐清洗机、储盐溶盐罐等的设计,并对等温淬火设备的发展进行了展望.     

Optimum design of flow distribution in quenching tank for heat treatment of A357 aluminum alloy large complicated thin-wall workpieces by CFD simulation and ANN approach

Based on the computational fluid dynamics (CFD) method, a quenching tank with two agitator systems and two flow-equilibrating devices was selected to simulate flow distribution using Fluent software. A numerical example was used to testify the validity of the quenching tank model. In order to take tank parameters (agitation speed, position of directional flow baffle and coordinate position in quench zone) into account, an approach that combines the artificial neural network (ANN) with CFD method was developed to study the flow distribution in the quenching tank. The flow rate of the quenching medium shows a very good agreement between the ANN predicted results and the Fluent simulated data. Methods for the optimal design of the quenching tank can be used as technical support for industrial production.