套筒类铸铁件卧浇爬芯单边浇冒口工艺

应用均衡凝固补缩技术,将立浇上雨淋浇口改为卧浇单边顶注浇注系统,消除了套筒类铸件的缩孔、缩松、夹渣、气孔等缺陷,成品率由50%～80%提高到97%以上.实践证明,卧浇"顶注优先冒口靠边"是解决套筒类铸件缩孔、缩松、渣气孔等缺陷的有效途径之一.     

大型半齿轮铸件的铸造工艺设计

针对砂型铸造工艺生产的大型半齿轮铸件在生产过程中出现的变形、缩松、缩孔、裂纹等铸造缺陷,采用模数法对大型半齿轮冒口补缩工艺进行计算,通过增加外冷铁,改进浇注系统,增加拉筋等措施对铸造工艺进行了优化.工艺改进后,产品的工艺出品率明显提高,变形、缩松、缩孔、裂纹等铸造缺陷基本消失.     

运用均衡凝固理论解决机床工作台缩松缺陷

机床工作台是厚大断面灰铁铸件,台面厚度在80~120 mm之间,在生产过程中非常容易出现T型槽缩松缺陷,通过运用均衡凝固技术进行工艺改进,充分利用厚壁灰铸铁的自补缩功能,消除了铸件的缩孔和缩松缺陷。批量生产证明,铸件废品率由15%左右降为0。     

龙门式加工中心立柱部件铸造工艺研究

以EGC2040龙门式加工中心立柱为研究对象,对其铸造工艺进行研究,通过Any Casting软件对铸件充型、凝固过程进行了数值模拟,对缩孔缩松缺陷进行预测,根据模拟与预测结果对原工艺进行优化,并使用三因素三水平正交实验确定最佳工艺参数。研究表明:采用阶梯式、多内浇道浇注方案,在浇注温度1 320℃、浇注速度80 mm/s、冷铁厚度70 mm条件下加工铸件,铸件品质良好,无明显缩孔缩松缺陷,符合生产要求。     

基于AnyCasting大型薄壁鞍座铸造工艺优化

针对大型薄壁铸件鞍座铸造过程中易产生缩松、缩孔缺陷等问题,基于AnyCasting模拟软件对鞍座的充型和凝固过程进行了模拟。根据模拟结果分析缩松、缩孔缺陷的位置分布,发现铸件内部有缩松、缩孔现象产生,并通过实际浇注试验对比缺陷位置以验证模拟结果的可信性。采用在热节位置添加内冷铁的改进方案,结果表明,原缺陷产生位置在凝固过程中优先凝固,消除了缩松、缩孔缺陷,为类似薄壁铸件实际生产提供相应指导。     

View Cast软件在星轮铸钢件铸造工艺优化上的应用

生产过程中发现星轮铸钢件有缩孔、缩松缺陷.运用ViewCast软件对其铸造工艺及凝固过程进行模拟.分析了缺陷形成的原因.根据模拟结果,再用V-Cast软件冒进行口尺寸改进、优化工艺的模拟.结果表明:优化工艺中的冒口尺寸和位置是合适的,实现了顺序凝固,消除了缩孔、缩松缺陷,保证了铸件质量.     

基于华铸CAE的核主泵支承座铸造缺陷分析及工艺改进

压水堆核电站主泵支承座在砂型铸造的过程中出现了缩松、缩孔等缺陷,为了解决该问题,采用华铸CAE软件纯凝固计算模块对铸件铸造工艺进行模拟,并预测了铸件产生缩松、缩孔的位置。基于铸件缺陷的分析进行了铸造工艺的优化。结果表明,优化工艺后生产的支承座有效地防止了缩松、缩孔等缺陷,效果显著。     

φ1300立式磨底座的铸造工艺改进

运用V-Cast软件对铸钢件φ1300立式磨底座铸造工艺进行凝固过程模拟,分析缩孔、缩松缺陷产生的原因.根据模拟结果,添加了冒口和保温材料,以优化工艺;最终获得了合适的工艺,消除了缩孔、缩松缺陷,保证了铸件质量.     

基于ProCAST的汽车制动鼓消失模铸造工艺优化

针对汽车制动鼓铸件在实际生产中存在的缩孔、缩松问题,通过ProCAST软件对制动鼓消失模铸造工艺进行数值模拟,分析了铸件温度场对铸件缩松缩孔缺陷的影响,并对消失模铸造汽车制动鼓工艺方案进行了优化。结果表明,采用底部注入式浇注系统,液态金属在充型过程中均匀平稳并且能够充满铸型型腔,通过在铸件顶部加环形冒口以及增加铸件顶部内壁壁厚,可以有效地改善凝固过程中的温度场,降低铸件出现缩松、缩孔的几率,使缩松、缩孔缺陷基本出现在直浇道中。对铸件进行X射线检测,实际生产汽车制动鼓铸件内部无缩松、缩孔缺陷,提高了铸件的合格率。     

运用均衡凝固理论解决燃气轮机壳体铸件的缩孔和缩松缺陷

燃气轮机壳体是厚大断面球墨铸铁件,壁厚在80~200mm之间,在生产过程中非常容易出现缩孔和缩松缺陷,运用均衡凝固理论进行工艺改进,充分利用厚壁球铁件的自补缩功能,消除了铸件的缩孔和缩松缺陷,生产验证表明均衡凝固技术作为工艺设计理论和方法,对生产高品质的铸件有普遍意义。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.