长条对称型消失模铸件的收缩不均性分析

通过对“特殊横壁”铸件的试验测试发现，长条对称型消失模铸件，如采用不同的浇注方案，其铸件的收缩率相差较大，采用水平卧式浇注，铸件对称的两边收缩率基本相同，而采用垂直立式浇注，铸件对称的上下收缩率相差较大，分析了长条对称型消失模铸件收缩不均性的原因，对此类铸件的工艺设计原则及浇注方案的确定进行了初步探讨。     

中型薄壁环形件消失模铸造工艺研究

针对中型薄壁环形铸件的结构特点,设计了阶梯式浇注系统,利用ProCAST软件对其消失模铸造充型和凝固过程进行了数值模拟分析。模拟结果表明该薄壁环形铸件不存在冷隔、浇不足等缺陷,也不存在明显的缩孔缩松缺陷。对此铸件进行生产试制,将5个铸件组合成一簇进行浇注,保障了较高的工艺出品率,试制铸件结构完整、轮廓清晰,无明显铸造缺陷,为消失模铸造中型薄壁环形件的高效率生产提供了依据。     

消失模铸造生产不锈钢阀门铸件

介绍了利用消失模工艺生产阀门铸件的试制过程。对不锈钢阀门消失模铸造的浇注位置选择、浇注工艺的设计、模样组合、涂料涂挂、装箱浇注和过程控制等方面进行了论述。     

5MD缸体铸造工艺优化

某工厂生产的5MD缸体体积小,适合一箱多型浇注,最初设计浇注工艺时采用底注式浇注系统,铸件出现冷隔、裂纹等缺陷。为了解决铸件出现的上述缺陷,首先对原工艺方案进行了模拟,对浇注系统进行分析之后改进工艺,在新工艺方案数值模拟结果中未发现铸件有缺陷。采用新工艺试制铸件,对铸件进行检测,也未发现有缺陷,因此,采用新工艺方案批量生产铸件,解决了5MD缸体存在的冷隔和裂纹缺陷,获得力学性能满足技术要求的优良铸件。     

差速器壳体铸件的V法铸造工艺初探

简单介绍了采用V法铸造工艺生产出口差速器壳体铸件的试制过程,对差速器壳体件分型面选取、模具制作、浇注系统设计,造型浇注等过程控制进行了探索和实践。     

铝合金缸体、缸盖的消失模铸造

介绍了利用消失模铸造工艺生产铝合金缸体、缸盖的试制过程,对铝合金缸体、缸盖铸件,模样组合,浇注系统,涂料涂挂,装箱浇注和过程控制等方面进行了详细论述。     

滑板铸件缩陷缺陷的解决

分析了床鞍滑板铸件产生缩陷的原因,并提出了相应的解决措施.通过在熔炼过程中调整废钢、生铁加入量,以调节铸件含碳量,使铸件凝固收缩率减小;更改分型面及浇注位置等一系列工艺措施,使铸件的废品得到了有效地控制.     

特大型后艉轴架的铸造工艺设计

针对某后艉轴架整体尺寸大、结构复杂、铸造易变形,且吨位大、壁厚大、补缩难度大等特点,采用了如下的工艺方案:地坑组芯造型,选取经验收缩率和工艺补正量,采用保温发热冒口,设置防变形和防裂拉筋,浇注系统设计等。经铸造数值模拟验证,工艺方案合理可行,且最终试制产品尺寸准确、铸件质量良好,为大型船用铸钢件生产提供了技术指导和参考。     

碳钢轮毂的消失模铸造

介绍了利用消失模工艺生产碳钢轮毂件的试制过程,对碳钢轮毂铸件,模样组合,浇注系统,涂料涂挂烘干,装箱浇注等过程控制方面进行了深入探索和实践。     

超高锰钢大型轧臼壁的试制

某铸件不仅表面质量要求极高,而且对铸件本体晶粒度有很高的要求.在样品试制前期,针对客户的要求对铸件的浇注系统和熔炼、浇注工艺进行了仔细的设计,并运用ProCAST软件对充型和凝固过程进行了模拟分析.     

汽轮机第十五级隔板铸造工艺设计

结合多年实践经验，对汽轮机铸铁隔板铸造工艺从铸造收缩率的选择、汽道出汽面积的控制、浇注工艺设计三个方面对其进行设计、分析，明确了铸造收缩率的确定方法，设计了汽道出汽面积，制定了浇注工艺，从而保证了隔板铸件的质量。     

均衡凝固技术在精密铸造阀瓣类铸件上的应用

采取均衡凝固理论设计的浇冒口,冒口既靠近热节又不在热节上,消除了冒口根部接触热节对铸件几何热节的影响,热冒口的模数可小于或等于铸件几何热节模数;同时控制浇注温度,减小钢液的液态收缩量;上述措施有效消除了精密铸造阀瓣类铸件的缩松缺陷,同时提高了工艺出品率。     

不锈钢刀阀体铸造工艺计算机辅助分析

借助SolidWorks进行三维造型,运用德国MAGMA软件：进行凝固过程的数值模拟,可预知体收缩类缺陷;充型过程的数值模拟,预知充型过程类缺陷如冷隔、卷气、夹渣等缺陷;应力应变场的模拟,用以分析铸件变形的趋势。通过计算机辅助分析,优化铸造工艺,提高新产品的开发速度。     

压铸件包紧力的动态分析

铝合金压铸件包紧力从模具内的冷却开始到顶出铸件的过程中,始终是动态变化的。模具与合金随温度变化对应有不同的热膨胀系数,模具设计时应根据不同压铸合金选择不同的收缩率。压铸生产中因为温度变化造成的顶出铸件故障可以通过调整温度来解决。     

A Free Thermal Contraction Method for Modelling the Heat-transfer Coefficient at the Casting/Mould Interface

Abstract

This study is intended to explore a simple and inexpensive method that is able to model the variation and distribution of the heat transfer coefficient at the casting/mould interface. It has been assumed that, in a rigid mould, the magnitude of interface gap size primarily depends on the thermal contraction of cast metal as it solidifies. Consequently, a free thermal contraction method has been developed to describe the thermal contact phenomena at the casting/mould interface, based on the above assumptions. This method has been used in the solidification simulations for three sand castings of different shapes. The numerical solutions of the simulations agree closely with the experimental results of the thermocouple measurements in the castings and their moulds. For the casting and mould materials involved, the empirical parameters in the equation of the heat transfer coefficient are the same for each of these cases, i.e. independent of the geometric shape of the castings.     

Development of a device for dynamical measurement of the load on casting and the contraction of the casting in a sand mold during cooling

To predict and control the residual stress present in sand castings manufactured via CAE (Computer Aided Engineering), the mechanical interaction between the casting and the sand mold during cooling must be determined experimentally. A device was developed in this study to determine the load on the casting caused by the resistance of the mold and the contraction of the casting during cooling. Our device consists of two modules that work simultaneously: a module containing a load cell, for measuring the load on the casting during cooling and a module containing an LVDT (Linear Variable Differential Transformer) for measuring the contraction of the casting during cooling. In performance verification testing, the device enabled the simultaneous measurement of the load on the sand casting and the contraction of the casting. This measurement was performed dynamically during the cooling process. Additionally, for the case where the contraction of the casting was hindered by the sand mold, the permanent deformation of the casting after shake out (which leads to residual stress in the casting) was successfully measured using our device.     

精密铸造特殊球阀

高铬铸铁空心球阀的精密铸造难度较大,球阀内部必须空心、全封闭,同时高铬铸铁的裂纹敏感性极强。采用δ=2mm薄钢板经冲压、组焊形成球形金属芯代替水玻璃砂芯(或陶瓷芯),成功铸造完成空心球阀阀体。     

Linear contraction of ductile iron castings

The effect of casting design on the linear contraction of ductile iron castings produced in clay- and silicate-bonded sand moulds has been studied. The designs included free and restrained square bar castings.

Free contraction of very thin sections of ductile iron in sand moulds was found to approach 1.35%. As sections increased to 25 mm thick, the contraction decreased linearly to 1.08% in silicate-bonded sand moulds, but to 0.90% in clay-bonded sand moulds.

For test pieces with end flanges which stimulated various degrees of constraint as would be experienced in a shaped casting, the contraction was found to be sensitive to the third power of the relative cooling time of the flange and the cast section. In conditions of high constraint, contraction could fall as low as 0.55%.

The data from this study represent a first attempt to provide a designer and toolmaker with realistic contraction allowances for shaped castings.     

农药泵铜合金阀体液态挤压工艺

采用液态挤压代替压力铸造及热模锻生产农药泵铜合金阀体，不仅消除了压铸件内部容易形成气孔，疏松及非金属夹杂的缺陷，而且减少了锻造设备的投资及提高了材料利用率和成品率，本文介绍了铜合金阀体液态挤压的模具结构及设计参数，分析了液态挤压的工艺参数及选择依据，产品的技术经济。     

真空压铸中高真空排气阀与薄片通道式排气阀的排气性能对比

利用自制盒状压铸试验模具,在650t冷室压铸机上,对传统的薄片通道式真空排气阀及高真空排气阀空压射动作的型腔背压进行了测量。在压射冲头静止状态下,对型腔的最大真空度等排气阀性能参数进行了试验测量,并系统研究了不同的真空压铸模具密封工艺对型腔内实际达到真空度的影响。分别利用两种不同的排气阀进行了A383铝合金的真空压铸,针对铸件上不同位置的密度进行了取样分析,对两种排气阀的排气性能以及应用于真空压铸工艺的可行性进行了评估。