Paper Title:
On the Problems of a Migrating Hot Spot
  Abstract

In this work the meaning of a migrating hot spot during solidification will be discussed. Initially, just after mould filling, global as well as local thermal centres, or hot spots, are established. This occurs at mass concentrations and heavy sections as the mould wall initially is at ambient temperature. However, these hot spots are found to be migrating during solidification. This migration influences any temperature measurement and subsequent thermal analysis, introducing uncertainties. It has also been found that common casting defects such as shrinkage porosity and metal expansion penetration can be associated with a migrating hot spot. In these cases the final position of the hot spot is located across the interface between the casting and the mould. The solidification starts at the mould walls and it was found that the columnar zone is affected by the migrating hot spot. The macrostructure was preserved using DAAS technique and it was revealed that an otherwise normal columnar zone because of the migrating hot spot had been affected. Based on these findings it is suggested that the migrating hot spot is making the columnar zone weaker and more susceptible for pressure differences arising during solidification.

  Info
Periodical
Edited by
A. Roósz, V. Mertinger, P. Barkóczy and Cs. Hoó
Pages
443-448
DOI
10.4028/www.scientific.net/MSF.649.443
Citation
L. Elmquist, A. Diószegi, "On the Problems of a Migrating Hot Spot", Materials Science Forum, Vol. 649, pp. 443-448, 2010
Online since
May 2010
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Gábor Fehérvári
Abstract:Two computer programs were used for simulation of continuous steel casting processes in frame of this work. In the same time industrial...
329
Authors: Hua Tan, Jing Chen, Xin Lin, Xiao Ming Zhao, Wei Dong Huang
Abstract:Laser rapid forming (LRF) is a new manufacturing technology, which has been developed on the basis of multi-layer laser cladding. In the LRF...
2301
Authors: H.J. Dai, H.B. Dong, H.V. Atkinson, Peter D. Lee
Abstract:A coupled cellular automaton-finite difference (CA-FD) model is used to simulate the detailed dendritic structure evolution of the...
129
Authors: Els Nagels, Ludo Froyen
Abstract:In this work the transition from columnar to equiaxed growth is studied during the solidification of the univariant eutectic L=> α(Al) +...
379
Authors: Waldemar Wołczyński, Wojciech Wajda, Edward Guzik
Abstract:Columnar or equiaxed structure selection and particularly the C→E transition in the solidifying massive rolls is shown as the result of...
174