Möglichkeiten und Grenzen der experimentellen Bestimmung des Schrumpf- und Kontraktionsverhaltes bei Stahl mit Hilfe des SSCC Versuches

Translated title of the contribution: Possibilities and constraints of the SSCC test to determine the shrinkage and contraction behaviour of steel

Florian Schneller

Research output: ThesisMaster's Thesis

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Abstract

During the solidification of steel the alloy specific density changes as a function of the temperature. As a result, shrinkage and contraction occur which induce stresses in the solidifying shell. In the continuous casting mould these stresses may result in shrink away of the shell from the mould wall. Consequently, the cooling rate will be reduced which further results in an uneven shell growth with an increased susceptibility to cracking. In this context, the most critical steel grades are peritectic steels according to service experience and laboratory investigations.In the continuous casting mould it is not possible to measure the shrinkage- and contraction-strains. However, using the SSCC (Submerged Splitt Chill Contraction) – Method – developed at the chair of metallurgy – it is possible to measure the contraction force of a solidifying shell around a cylindrical test body. The aim of the present study was the evaluation of the possibilities of this test method in order to identify critical steel grades. Furthermore, the sensitivity as well as the limits of this experiment with respect to the measured contraction force was analysed. Applying continuously improved test body geometries, the experimental results showed the best reproducibility at high cooling rates (uncoated test bodies), higher superheat and using an elastic refractory material between the upper- and under part of the test body. The analysis of the measured time-dependant contraction force in terms of the maximum force, Fmax, as well as the slope of the curve, dF/dt, showed a good differentiation of 0.11 and 0.30 %C steels (0,3 %Si, 1,5 %Mn, 0,003 %P and %S). Based on the results of the improved test body geometry the SSCC - test represents an appropriate method to investigate the behaviour (shrinkage, contraction, uneven shell growth, etc.) of steels at the early stages of solidification.
Translated title of the contributionPossibilities and constraints of the SSCC test to determine the shrinkage and contraction behaviour of steel
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Pierer, Robert, Co-Supervisor (internal)
  • Bernhard, Christian, Supervisor (internal)
Award date1 Jul 2011
Publication statusPublished - 2011

Bibliographical note

embargoed until null

Keywords

  • shrinkage
  • contraction
  • peritectic
  • steel

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