Experimental and numerical analysis of effect of cooling rate on thermal–microstructural response of spheroidal graphite cast iron solidification

Abstract

OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This work presents an experimental and numerical study of the solidification process of an eutectic spheroidal graphite cast iron (SGI). The effect of the cooling rate on the thermal-microstructural response is particularly analysed. To this end, experiments as well as numerical simulations were carried out. The experiments consisted in a solidification test in a wedge-like casting such that different cooling rates were measured at specific positions along the part. A metallographic analysis was also performed in five locations of the sample with the aim of obtaining the number and size of graphite nodules at the end of the process. The numerical simulations were made using multinodular based and uninodular based models. These two models predicted similar results in terms of cooling curves and nodule counts. Besides, good experimental-numerical agreements were obtained for both the cooling curves and the graphite nodule counts.

An oil sloshing study: adaptive fixed-mesh ALE analysis and comparison with experiments

“…Interface problems, either, free-surface [5,6], a thermally coupled analysis considering phase-change [7,8], or even, solid mechanics problems with stresses location, damage or plasticity [9,10,11], are promising cases where the use of adaptivity is relevant because thin layers of the full domain contains the most important information of the global behavior of the problem. In this work an adaptive xed-mesh ALE method is used to numerically approximate the sloshing of a rectangular tank partially lled with a domestic oil subjected to a controlled movement generated by a shake table.…”

On the Effect of Pouring Temperature on Spheroidal Graphite Cast Iron Solidification

“…This specific analysis constitutes an extension of another study [20] which emphasized the influence of the cooling rate on the microstructural evolution of the analyzed part. In order to analyze the evolution of the microstructure during the cooling process, two solidification experiences, i.e., two experiences with filling temperatures of 1200 °C and 1250 °C, were carried out in a wedge-like mold.…”

“…The subsequent growth takes place via carbon diffusion through the austenite envelope. The main aspects of the nucleation and growth laws considered in this approach laws are described below (details of this model can be found in reference [20]). …”

“…In order to take into account the phase changes that occur during the cooling process, the well-known energy equation is considered [17][18][19][20]:…”

“…According to the multinodular theory of nucleation and growth, during the cooling process of a nodular cast iron with eutectic composition, once the eutectic temperature is reached, austenite and graphite nucleate independently in the liquid (austenite growing in a dendritic shape and graphite in a spherical shape) such that at a certain instant (experimentally determined in reference [16]), graphite is enveloped by the thinnest arms of dendritic austenite and subsequent growth proceeds by carbon diffusion through this phase. It should be mentioned that the multinodular-based model developed by Boeri [16] was widely used and validated with the experiments in reference [20].…”