Study of obtaining in cooled steel chill mould of hollow cylindrical casting from aluminum alloy for rolling of pipe billet

Hollow cylindrical casting made of aluminum alloy in cooled steel chill mould for the purpose of rolling pipe billet are obtained. The average temperature of the wall of the mould and the casting at the time of its extraction is determined with the use of constructive calculations. The results are compared with the experiment. There are no cracks in the resulting hollow casting, which allows it to be used for the subsequent rolling of pipes.

Computer Simulation of Centrifugal Casting Process Using FLOW-3D

Centrifugal casting process is one of the potential manufacturing techniques used for producing functionally graded materials viz., composite materials or metallic materials which have high differences of density among constituents. In this process, the fluid flow plays a major role and understanding the complex flow process is a must for the production of defect-free castings. Since the mold spins at a high velocity and the mold wall being opaque, it is impossible to visualise the flow patterns in real time. Hence, in the present work, the commercial CFD code FLOW-3DTM, has been used to simulate the mold filling sequence for a simple hollow cylindrical casting during vertical centrifugal casting process. Effect of various spinning velocities on the fill pattern during vertical centrifugal casting process is being investigated.

Determination of Interface Heat Transfer Coefficient for Cylindrical Casting by Using an Inverse Heat Conduction Model

For accurate simulation of the casting process with permanent mold, the correct Interfacial Heat Transfer Coefficient (IHTC) is highly important. However, its value is not easily obtained through the experimental or theoretical method in the complex solidification process. In this paper, an inverse conduction model is introduced to determine the IHTC at casting-mold during solidification of the cylindrical casting based on the temperature-measured data. The established inverse model is verified to be a feasible and effective tool for estimation of the metal-mold IHTC during solidification of cylindrical casting by the analysis of calculated results.

Effect of Pulling Velocity on the Unidirectional Solidification Phenomenon of DZ417G Superalloy

In this study, the influence of pulling velocity on temperature field, fluid field and grain structure of a unidirectionally solidified superalloy DZ417G cylindrical casting was investigated by using a 3D cellular automaton finite element (CAFE) model within commercial software CALCOSOFT. The predictions show that temperature distribution in the casting is well in accordance with the experiment result. The solidification front and fluid field are sensitive to changes in pulling velocity. And the pulling velocity should be controlled less than 0.5 mm/s in our experiment so as to effectively decrease the grain number and mean grain deviation.

The Effect of Fluid Convection on Microstructures of Directionally Solidified Castings

Fluid convection during solidification of castings will influence the final structures of the castings. A vertical cylindrical casting set-up has been designed to provide two zones of solidification simultaneously with two moving fronts directionally upward and directionally downward, respectively. This two zone directional solidification casting was composed of a cylindrical Furan sand mold with a water chilled center hole block at the center of the casting. Experimentally it was observed that the cooling rates at different locations of the downward zone were much more even than those of the upward one and this is considered to be the result of a more even temperature distribution along the downward front moving zone due to stronger fluid convection. Fluid convection tends to mix up the liquid and results in a more even temperature distribution and a lower degree of segregation of the element molybdenum which has a strong tendency to segregate to the carbide in ductile iron. The characteristics of the matrix microstructure and the growing direction of carbide of this directionally solidified ductile iron has been investigated with SEM and EBSD techniques.