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Temperature and Thermal Stress Distribution for Metal Mold in Squeeze Casting Process

KHChang,GCJang,CHLee,SHLee,

材料科学技术学报 , 2008,
Abstract: In the squeeze casting process, loaded high pressure (over approximately 100 MPa) and high temperature influence the thermo-mechanical behavior and performance of the used metal mold. Therefore, to safely maintain the metal molds, the thermo-mechanical characteristics (temperature and thermal stress) of metal mold in the squeeze casting must be investigated. In this paper, temperature and thermal stress distribution of steel mold in squeeze casting process were investigated by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis considering temperature-dependent thermo- physical and mechanical properties of the steel mold.
An Analysis of Thermal Elastoplastic Behavior of Continuous Casting Slab Mold
板坯连铸结晶器的热弹塑性力学分析

LIU Xudong,ZHU Miaoyong,CHENG Nailiang,
刘旭东
,朱苗勇 程乃良

金属学报 , 2006,
Abstract: Three-dimensional finite-element thermal stress model was established to predict the thermal distortion and stress distribution in a continuous casting slab mold during production. The effects of copper plate thickness, water slot depth and nickel layer thickness on copper plate distortion and stress were investigated. The results show that the maximum distortions of wide and narrow faces of the copper plate are 0.245 mm and 1.01 mm, respectively. During operation, the distortion and thermal stress decrease with decreasing copper plate thickness and increasing water slot depth, while the effects of the thickness of nickel layer coating on the copper plate distortion and thermal stress distribution are not obvious.
Study on the Thermal Behavior in Slab Continuous Casting Mold
板坯连铸结晶器热行为研究

Xu-Dong LIU,
刘旭东
,朱苗勇,程乃良

金属学报 , 2006,
Abstract: Three-dimensional finite-element heat-transfer model was established to predict the temperature distribution in a continuous casting mold during steelmaking. The effects of copper plate thickness, water slot depth and nickel layer thickness on copper plate temperature are analyzed in detail. The results show that decreasing copper plate thickness and nickel layer thickness, and increasing water slot depth are available in decreasing the copper plate temperature, and therefore improving the mold life.
EXPERIMENTAL RESEARCH AND NUMERICAL SIMULATION OF MOLD TEMPERATURE FIELD IN CONTINUOUS CASTING OF STEEL
XS Zheng,MH Sha,JZ Jin,
X.S.
,Zheng,M.H.,Sha,J.Z.,Jin

金属学报(英文版) , 2006,
Abstract: Mold is the heart of the continuous casting machine. Heat transfer and solidification in a water- cooled mold are the most important factors during the continuous casting of steel. For studying the temperature distribution of a mold wall, a simulated apparatus of mold was designed and experiments were performed by it. The measured results indicated that the mold wall temperature approaches the temperature of cooling-water. An equivalent thermal-conductivity coefficient was proposed and deduced on the basis of the conclusion of the experiments. This coefficient was applied to solve the heat transfer between the melt and cooling water, and to characterize the heat transfer capacity of the mold. By this equivalent thermal-conductivity coefficient, it is very easy and convenient to numerically simulate the solidification process of continuous casting. And the calculation results are in agreement with the experiments. The effects of custing speed and water flow rate on the mold temperature field were also discussed.
Microstructure and Glass Phase of Inorganic Binder Coated on Mold for Thin Casting  [PDF]
Eun-Hee Kim,Geun-Ho Cho,Yeon-Gil Jung,Je-Hyun Lee,Baig-Gyu Choi,Chang Young Jo
Journal of Nanomaterials , 2012, DOI: 10.1155/2012/126567
Abstract: A new dual dipping process has been introduced for the increase in the fracture strength of casting mold through the effective glassification of inorganic binder precursors. Two different dipping processes have been employed to investigate the reactivity of the precursors. Process I is that the substrate was coated with a sodium oxide (Na2O) precursor through dipping in the solution, and then a silicon dioxide (SiO2) precursor was coated onto the substrate coated with the Na2O precursor. Process II is the inverse coating sequence for process I. In the case of the mold prepared by process I, the glass phase converted from the precursors is uniformly observed at the surface of the particle and the interface between particles, compared with that by process II, inducing that the fracture strength of the mold prepared by process I is significantly improved. In addition, when the PDMS without a sol-gel reaction was used as the SiO2 precursor, especially in process II, the glass phase is not absolutely observed at the surface of the particle owing to the evaporation of PDMS and Na ion during the heat treatment, resulting in the collapse of the mold sample after the heat treatment. 1. Introduction Recently, the convert mold process has been introduced to fabricate molds in a thin casting [1, 2]. The convert mold process has many advantages, such as high strength, excellent collapse, easy processability, and high thermal stability, making it useful in fabricating components of automobile and aircraft. Typically, the convert mold process is divided into five main processes: (1) fabricating the starting mold coated with an organic binder, (2) dipping the coated mold into a slurry containing inorganic binder precursors, (3) 1st drying for 1?h at 80°C, (4) 2nd drying for 1?h at 200°C, and (5) heat treatment for 1?h at 1000°C, resulting in the conversion of the organic binder-coated mold to the inorganic binder-coated mold [3, 4]. The hydrolysis and condensation reactions (generally called a sol-gel reaction) and glassification take place during the above (3 and 4) and (5) processes, respectively [5–7]. The mechanical and thermal properties of the mold are induced from the glass phase generated during the heat treatment process, even though the organic binder is decomposed after the heat treatment. Therefore, the generated glass phase must be homogeneously formed on the surfaces of starting particles in the mold as well the conversion efficiency of inorganic binder precursors into the glass phase should be increased, which are related to the reactivity between
NUMERICAL SIMULATION OF CASTING''S MOLD FILLING PROCESS
NUMERICAL SIMULATION OF CASTING'S MOLD FILLING PROCESS

JX Zhou,RX Liu,LL Chen,DM Liao,HS Wei,
J.X.
,Zhou,R.X.,Liu,L.L.,Chen,D.M.,Liao,H.,S.,Wei

金属学报(英文版) , 2005,
Abstract: Numerical simulation of casting's mold filling process is the main and the most important aspect of the foundry CAE technology. But it is time-consuming; it may take dozens of hours or several days. While with the development of computer hardware, numerical simulation of casting's mold filling process has made rapid progress. The simulation results, therefore, have become more and more practical. This study tries to find some clues of the computational time of mold filling process. Firstly, this paper introduces mathematic model and the basic route of numerical simulation of casting's mold filling process. Then the computational time of mold filling process has been carefully studied, and some new and useful results have been gained from the study of the computational time. Finally, this paper has given some real applications of numerical simulation of casting's mold filling process.
Modeling of Mold Filling and Solidification in Lost Foam Casting
Fengjun LI,Houfa SHEN,Baicheng LIU,
FengjunLI
,HoufaSHEN,BaichengLIU

材料科学技术学报 , 2003,
Abstract: Based on the characteristics of the lost foam casting (LFC) and the artificial neural network technique, a mathematical model for the simulation of the melt-pattern interface movement during the mold filling of LFC has been proposed and experimentally verified. The simulation results are consistent with the experiments in both the shapes of melt front and filling sequences. According to the calculated interface locations, the fluid flow and the temperature distributions during the mold filling and solidification processes were calculated, and the shrinkage defect of a lost foam ductile iron casting was predicted by considering the mold wall movement in LFC. The simulation method was applied to optimize the casting design of lost foam ductile iron castings. It is shown that the model can be used for the defects prediction and for casting design optimization in the practical LFC production.
Diagnosis parameters of mold filling pattern for optimization of a casting system  [PDF]
Jun-Ho Hong,Young-Sim Choi,Ho-Young Hwang
China Foundry , 2012,
Abstract: For optimal design of a gating system, the setting of diagnosis parameters is very important. In this study, the permanent mold casting process was selected because most of the other casting processes have more complicated factors that influence the mold filling pattern compared to the permanent mold casting process, such as the surface roughness of mold, gas generation from the mold wash and binder of sand mold, and the gas permeability through a sand mold, etc. Two diagnosis parameters (flow rate difference and arrival time difference) of molten metal flow pattern in the numerical simulation are suggested for design of an optimum casting system with a permanent mold. The results show that the arrival time difference can be used as one important diagnosis parameter of the complexity of the runner system and its usefulness has been verified via making aluminum parts using permanent mold casting (Fig. 9).
Hot mold casting process of ancient East India and Bangladesh  [PDF]
Barnali Mandal,Prasanta Kumar Datta
China Foundry , 2010,
Abstract: Ancient casting process for production of brass or bronze utensils and icons were made in hot molds using clay molded investment casting or piece mold process, as presumed by archaeologists. Piece mold process is still traditionally practiced in many parts of Eastern India and Bangladesh along with investment casting process. Incidentally, Bengal artisans are more accustomed to piece mold process unlike tribal artisans who practiced investment casting process. This piece mold casting process has been reconstructed to get the idea of metal characteristics in order to investigate ancient casting process of Bengal and Bangladesh. The characterization of ancient archaeo-metal products come to a type of cast Cu-Sn-Zn-Pb type quaternary alloy produced by a slow freezing process. Though these alloys physically differ from the traditional cast alloy of binary Cu-Zn type brass, the physical characteristics are similar to the binary cast alloy character. This investigation throws light on the similarity of the production processes by which ancient artisans probably produced cast metal products.
Using finite difference method to simulate casting thermal stress  [PDF]
Liao Dunming,Zhang Bin,Zhou Jianxin
China Foundry , 2011,
Abstract: Thermal stress simulation can provide a scientific reference to eliminate defects such as crack, residual stress centralization and deformation etc., caused by thermal stress during casting solidification. To study the thermal stress distribution during casting process, a unilateral thermal-stress coupling model was employed to simulate 3D casting stress using Finite Difference Method (FDM), namely all the traditional thermal-elastic-plastic equations are numerically and differentially discrete. A FDM/FDM numerical simulation system was developed to analyze temperature and stress fields during casting solidification process. Two practical verifications were carried out, and the results from simulation basically coincided with practical cases. The results indicated that the FDM/FDM stress simulation system can be used to simulate the formation of residual stress, and to predict the occurrence of hot tearing. Because heat transfer and stress analysis are all based on FDM, they can use the same FD model, which can avoid the matching process between different models, and hence reduce temperature-load transferring errors. This approach makes the simulation of fluid flow, heat transfer and stress analysis unify into one single model.
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