Elimination of Hot Tears in Steel Castings by Means of Solidification Pattern Optimization

Petr Kotas, Cem Celal Tutum, Jesper Thorborg, Jesper Henri Hattel

    Research output: Contribution to journalJournal articleResearchpeer-review

    1 Downloads (Pure)

    Abstract

    A methodology of how to exploit the Niyama criterion for the elimination of various defects such as centerline porosity, macrosegregation, and hot tearing in steel castings is presented. The tendency of forming centerline porosity is governed by the temperature distribution close to the end of the solidification interval, specifically by thermal gradients and cooling rates. The physics behind macrosegregation and hot tears indicate that these two defects also are dependent heavily on thermal gradients and pressure drop in the mushy zone. The objective of this work is to show that by optimizing the solidification pattern, i.e., establishing directional and progressive
    solidification with the help of the Niyama criterion, macrosegregation and hot tearing issues can be both minimized or eliminated entirely. An original casting layout was simulated using a transient three-dimensional (3-D) thermal fluid model incorporated in a commercial simulation software package to determine potential flaws and inadequacies. Based on the initial casting process assessment, multiobjective optimization of the solidification pattern of the considered steel part followed. That is, the multiobjective optimization problem of choosing the proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity, the macrosegregation pattern, and primarily on hot tear formation.
    Original languageEnglish
    JournalMetallurgical and Materials Transactions B - Process Metallurgy and Materials Processing Science
    Volume43
    Issue number3
    Pages (from-to)609-626
    ISSN1073-5615
    DOIs
    Publication statusPublished - 2012

    Fingerprint

    Dive into the research topics of 'Elimination of Hot Tears in Steel Castings by Means of Solidification Pattern Optimization'. Together they form a unique fingerprint.

    Cite this