汽车转向节的铸造工艺设计及数值模拟

本文根据转向节的结构特点,对转向节进行铸造工艺设计,在铸件的上耳和法兰盘处设置两个保温冒口,以确保对铸件的补缩和顺序凝固.运用Pro/E对铸件进行三维造型,然后使用ViewCast铸造模拟软件对铸件的凝固过程进行模拟计算,模拟结果表明:在铸件下耳处出现缩孔和缩松缺陷.根据模拟结果并结合理论分析,在下耳处设置一个暗保温冒口对铸件进行补缩,再次模拟结果表明:只在冒口内产生了少量的缩孔和缩松,铸件的缺陷已经完全消失.     

薄壁铝合金铸件低压铸造的数值模拟与工艺优化

利用ViewCast软件研究了薄壁铝合金筒状铸件的低压铸造充型凝固过程,获得了低压铸造过程中温度场、流动速度场的分布.模拟结果显示,铸件上法兰处将产生缩孔、缩松缺陷.根据模拟结果及理论分析改进初始工艺,在产生缺陷的上法兰处安放冒口.对改进后的工艺重新进行模拟,结果表明,冒口有效地补缩了上法兰部位,消除了缩孔、缩松缺陷.     

头部链轮体的铸造工艺设计与计算机模拟

应用ViewCast软件对头部链轮体铸件进行充型及凝固过程模拟,预测到在铸件的轮缘和轮毂处易产生缩孔,缩松等铸造缺陷.通过对铸件结构分析.采取放置冒口和冷铁的工艺措施,消除了缩孔、缩松等缺陷.     

CAE技术在轴承箱体铸造工艺优化中的应用

利用华铸CAE软件对YL14000B型烟机轴承箱体的充型凝固过程进行了模拟分析,预测了该铸件原铸造工艺存在冒口过大而导致的补缩过剩、后轴承座热节处存在集中缩孔、底座热节处存在疏松等缺陷.通过采取减小冒口尺寸、增加热节处内冷铁数量和加宽补缩通道等措施;再次进行CAE数值模拟,发现上述缺陷得到了有效消除.实际生产结果表明,冒口根部无集中缩孔,铸造工艺出品率由61%提高到了71%,节约钢液660 kg,降低了生产成本,铸件质量也得到了提高.     

采用改进随形压边冒口消除轴套铸件缩孔

介绍了轴套的铸件结构及技术要求,对铸件进行工艺分析后,分别对边冒口工艺和随形长缝隙压边冒口工艺进行模拟分析,对比发现:2种工艺虽然都在热节处形成孤立液相区,但随形长缝隙压边冒口工艺比边冒口工艺的孤立液相区形成的时间晚,补缩效果较好。采用随形长缝隙压边冒口工艺进行试生产时发现,虽然铸件在尺寸、外观和力学性能方面均满足要求,铸件在热节处的缩孔、缩松问题仍然没有得到解决,后来在压边部位添加凸块的随形压边冒口,铸件本体解剖后没有缩孔缺陷。     

静压线生产球墨铸铁轮毂铸件的铸造工艺

介绍了轮毂铸件的结构及技术要求,根据铸件结构特点,设计了侧冒口补缩工艺和压边冒口补缩工艺,利用MAGMA数值模拟软件进行模拟分析,结果表明:选用压边冒口补缩工艺,补缩通道始终畅通,冒口对铸件进行液态补缩,在凝固过程后期,冒口颈处能够及时凝固,铸件依靠石墨化膨胀自补缩来抵消收缩,而且铸件先于冒口颈凝固,补缩通道在铸件凝固过程中始终是畅通的,满足顺序凝固的要求,因而获得内部致密的铸件。首件试制后的结果显示:选择用压边冒口生产的轮毂组织致密性好,未出现缩孔、缩松缺陷,说明压边冒口的补缩作用效果明显,目前,已经进行了小批量生产,未收到客户关于铸件加工后有缺陷的反馈。     

球铁齿轮箱体铸造工艺的优化

采用带气流预紧实的KW高压造型机生产地铁齿轮箱上箱体球铁件。由于按原工艺方案生产的铸件多处厚大部位均出现了缩孔、缩松缺陷,利用华铸CAE软件进行了工艺模拟,结果显示：由于冒口颈凝固封闭的时间过早,远离冒口处的热节不能补缩,导致缩松、缩孔缺陷的形成。通过调整冒口尺寸和冒口颈尺寸,在砂芯中部设置冷铁以及进行浇注系统改进等工艺措施,延长了冒口补缩通道畅通时间,提高了补缩效率。试产铸件经解剖和X光探伤确认,缩孔和缩松已被消除,铸件已成功地进行批量生产。     

轴瓦体铸铁件的数值模拟和铸造工艺优化

根据轴瓦体铸铁件的结构特点,对轴瓦体进行铸造工艺设计。在铸件一侧设计浇注系统,在铸件顶部设计了冒口来实现对壳体进行补缩。用CAD软件建立了铸件的三维模型,运用ViewCast模拟软件对轴瓦体进行凝固过程模拟,发现在铸件顶部及热节处存在缩孔缩松等缺陷。根据数值模拟结果并结合理论分析,通过改用保温冒口的方法改进了铸造工艺方案。结果表明,只在热节处出现少量的缩松,铸件的缺陷已经消失。     

消除球墨铸铁铸件缩陷缺陷的措施

介绍了球墨铸铁入料座的铸件结构和铸造工艺。采用封闭式浇注系统,横浇道处搭接部位设置纤维过滤网挡渣,顶部设置冷冒口。为解决铸件出现的缩陷缺陷,利用数值模拟软件进行分析,最后通过提高顶冒口高度,并在铸件厚大部位最后凝固区域增加与浇注系统连接的热侧冒口,增强冒口的补缩能力,解决缩陷、缩孔、缩松缺陷问题。     

大型铸钢支架铸造工艺数值模拟与优化设计

利用ProCAST软件对大型铸钢支架进行充型和凝固模拟,分析冒口与冷铁的数量和位置对铸件缩松缩孔分布的影响。通过模拟结果优化底注式铸造工艺,逐步使缩松缩孔缺陷从铸件转移到冒口内部,将缩松率降到最低,保证铸件的致密性,得到高质量的铸件。     

冲击座铸造工艺设计及优化

介绍了冲击座铸件的结构及其工艺设计,包括每型件数、浇注系统形式及内浇道、横浇道和直浇道的截面积、浇注时间、冒口及冷铁设计等。初始铸造工艺只采用冒口补缩,模拟发现该工艺未能完全消除缩孔缺陷,据此对铸造工艺进行了改进,在孤立热节区设计冷铁。对改进后的铸造工艺进行模拟,结果显示,缩孔缺陷已完全可以消除。     

消除ZG15Mn磨辊铸钢件缩松缺陷的措施

ZG15Mn磨辊铸钢件属于低碳低合金钢厚大铸件,易产生夹杂、心部缩松、晶粒粗大等缺陷.第一次工艺方案是在铸件上方设2个圆柱形明冒口,结果在两冒口之间存在缩松;第二次工艺方案是在铸件上方设3个圆柱形明冒口,结果在3个冒口之间存在严重缩松.通过对缺陷原因进行分析,认为缩松是由于冒口的热作用很大,冒口与缩松区温度差较小,在最后凝固时,缩松区得不到冒口的有效补缩,造成了缩松.改进后的工艺方案是在铸件正上方设置一个圆柱形明冒口,冒口下设置补贴,形成顺序凝固,冒口向四周均匀补缩,使得铸件外圆的末端区作用发挥出来,从而使中间缩松区消失.经生产验证,新工艺不仅解决了缩松问题,而且铸件质量稳定.     

Numerical simulation and optimization of shell mould casting process for leaf spring bracket

Although the shell mould casting process has a wide range of application in many fields,the prediction of casting defects is still a problem.In the present work,a typical leaf spring bracket casting of ZG310-570 was fabricated by shell mold casting.The finite element model and ProCAST software were utilized for simulating the filling and solidification processes of the casting;and the formation mechanism of the gas pore,and shrinkage porosity defects were analyzed.The results indicate that the gas pore and shrinkage porosity defects are formed due to air entrapment,insufficient feeding and non-sequential solidification.Subsequently,through changing the position of risers,adding a connecting channel between the risers,and setting blind risers at the U-shaped brackets,an optimized gating and feeding system was established to improve the quality of the casting.After optimization,the gas pore and shrinkage porosity defects of the leaf spring bracket casting are effectively eliminated.The experiment results with the optimized casting process are in good agreement with the numerical simulation,which verifies the validity of the finite element model in the shell mould casting.     

基于数值模拟的大型薄壁铝合金件差压铸造工艺设计

将传统工艺和现代计算机模拟技术相结合,利用View Cast软件对薄壁铝合金筒体铸件凝固过程进行了分析,通过凝固过程时间分布预测了缩孔缩松产生的位置。采用加设缝隙式内浇道和增大冒口尺寸的方法对初始铸造工艺方案进行了优化。再次模拟表明,改进后的方案合理可行,铸件实现了充分补缩和顺序凝固,消除了缩孔（松）等缺陷。     

Optimization of investment casting process for K477 superalloy aero-engine turbine nozzle by simulation and experiment

In order to reduce the shrinkage porosity of nickel-based superalloy castings in the investment casting process, the effects of different gating systems on mold filling, solidification process, and prediction of shrinkage porosity of aero-engine turbine nozzle castings were investigated by simulation and experimental methods. Results show that the design of the vertical runner would cause greater turbulence of the melt in the riser during the mold filling process, and the outer runner is not necessary. With the decrease in number of runners, the hot spot moves down towards the casting, and the shrinkage and porosity defects are formed in the casting below the riser. In the original designs, a certain tendency of shrinkage and porosity defect is found in the vanes, inner rings, and outer rings of the castings by both simulation prediction and experiment. Finally, based on the processing optimization, the aero-engine turbine nozzle casting with no shrinkage and porosity defects is obtained.

     

Numerical simulation of low pressure die-casting aluminum wheel

The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC) of an aluminum wheel. By analyzing the mold-filling and solidification stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim/spoke junctions, which is in consistence with the X-ray detection result. The distribution pattern of the defects has also been studied. A solution towards reducing such defects has been presented. The cooling capacity of the mold was improved by installing water pipes both in the side mold and the top mold. Analysis on the shrinkage defects under forced cooling mode proved that adding the cooling system in the mold is an effective method for reduction of shrinkage defects.     

基于有限元CAE的回转体零件凝固工艺数值优化

根据有限元CAE对回转体铸钢件的凝固进程进行了数值模拟。通过CAE反馈信息进行了凝固工艺的数值优化设计。模拟表明，按照传统比例法设计的冒口能够保证铸件质量，但冒口数目多，工艺出品率偏低。通过减少冒口数目并适当设置冷铁，既消除缺陷，又提高出品率。通过模拟优化的实施，预测工艺出品率将提高12％。     

门框底衬铸钢件的铸造工艺设计及数值模拟

运用传统方法设计了门框底衬铸钢件的铸造工艺:包括分型面、浇注位置的选择、铸造工艺参数的确定以及浇注系统、冒口、冷铁的设计.根据铸件形状较复杂的特点,设计了两个内浇道;将铸件划分为4个补缩区域进行补缩,并配合冷铁来实现铸件的顺序凝固.用Pro/E软件建立了铸件的三维模型,采用ViewCast铸造模拟软件对铸件的凝固过程进行了模拟计算.模拟结果显示,在门框底衬凸台处会产生缩孔、缩松缺陷.根据数值模拟结果并结合理论分析,对铸造工艺方案进行了优化.通过改进工艺,最大程度地消除了铸造缺陷,从而获得了合理的铸造工艺方案.     

球铁升降机铸件铸造工艺计算机模拟优化设计

通过对用湿砂型生产的球铁升降机铸件凝固组织和固相转变的模拟,预测了其凝固过程、组织和性能情况,并通过计算机模拟对原工艺方案进行了优化。新工艺只有一个内浇道、两个发热冒口,并且没有采用冷铁,生产出的铸件没有缩孔、缩松和夹渣缺陷,工艺出品率也从最初的50%提高到了65%。