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On the Effect of Hot Rolling on Inclusion Size and Distribution in a Cast AISI 1070 Steel Railroad Wheel
International Journal of Metalcasting
  • Jacob M. Summers
  • Soumava Chakraborty
  • Laura Bartlett, Missouri University of Science and Technology
  • Ronald J. O'Malley, Missouri University of Science and Technology
  • Mario F. Buchely, Missouri University of Science and Technology
  • Richard Pilon
Abstract

The goal of this work is to examine the effect of hot deformation on shrinkage porosity and nonmetallic inclusions in an AISI 1070 grade steel industrially produced wheel casting. Steel cleanliness is an important consideration as it influences the mechanical properties of the final product. A high density of porosity and inclusions have been shown to be detrimental for mechanical properties, especially during hot rolling. Using a laboratory-scale rolling mill, cast preforms were subjected to a 66% cumulative reduction to determine the effect of thermomechanical processing on void closure and inclusions that may produce anisotropy in mechanical properties. Quantitative automated feature analysis, AFA, of inclusion type, size, morphology, and distribution was conducted utilizing an Aspex PICA 1020 scanning electron microscope to determine differences in inclusions and shrinkage porosity in the as-cast and as-rolled conditions. The results were compared with previously reported impact toughness values which indicated a trend with MnS projected length and average impact toughness in the T-L orientation. Reduction in shrinkage porosity was also verified utilizing 3D micro-X-ray CT scans. The AFA results showed a decrease in shrinkage porosity from 177 ppm in the as-cast condition to less than 35 ppm after rolling. Pores were in general much smaller and widely distributed after hot rolling and this would suggest improved impact properties. Analysis of nonmetallic inclusions revealed three primary categories of inclusions that included MnS, Al2O3, and complex inclusions that mainly consisted of MnS with an Al2O3 core, with small quantities of mixed silicates of Mn and Al and calcium aluminates (CaAl2O4).

Department(s)
Materials Science and Engineering
Comments

Missouri University of Science and Technology, Grant None

Keywords and Phrases
  • hypoeutectoid steel,
  • impact toughness,
  • inclusion analysis,
  • micro-X-ray CT scans,
  • projected length,
  • SEM AFA,
  • void closure
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2023 Springer, All rights reserved.
Publication Date
1-1-2022
Publication Date
01 Jan 2022
Citation Information
Jacob M. Summers, Soumava Chakraborty, Laura Bartlett, Ronald J. O'Malley, et al.. "On the Effect of Hot Rolling on Inclusion Size and Distribution in a Cast AISI 1070 Steel Railroad Wheel" International Journal of Metalcasting (2022) ISSN: 2163-3193; 1939-5981
Available at: http://works.bepress.com/mario-buchely/42/