In this research, a new semi-analytical model is presented for the strand surface temperature in the continuous casting of steel. Firstly with a dimensional analysis approach a general relation between the strand surface temperature and the other effective variables such as conductivity of the steel, pouring temperature, casting velocity, distance from the meniscus, volume rate of cooling water, solidus temperature and heat flux density at the meniscus is deduced. The constants appeared as coefficients or powers of variables in presented relation were computed by a numerical simulation of continuous casting for a breakout bloom. The resulted semi-analytical model for strand surface temperature was extended to predict the solidified shell thickness. The resulted semi-analytical model was validated with comparison to experimental, analytical and numerical results of slab, billet and bloom and good agreement was seen. The new presented model at this research is in versus of controllable parameters and specifications of the mold and it can be used for design of a process control system for continuous casting of slab, billet and bloom.

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Aluminum powder in tube compaction with a 25 mm front plug through equal channel angular extrusion (ECAE) at room temperature was modeled using the finite element analysis package ABAQUS. The Gurson model was used in modeling this process. 2-D simulations in a 90°angle die showed better consolidation of powder near the inner edge of the die than the outer edge after one pass of ECAE but almost full densification occurs after two passes. The effect of hydrostatic pressure on densification of the powder was investigated by using two plugs varying in length dimension. The results obtained from the simulations were also compared with experiments conducted to compact aluminum powder with mean particle diameter of 45 lm. Optical microscopy, microhardness test, and density measurements confirmed the simulations. The simulations were extended to powder compaction in a 60°and 120°angle die. It was found that one pass of ECAE is sufficient to consolidate the aluminum powder completely and uniformly in a 60°a ngle die, whereas the material is still porous in a 120°angle die.