Prediction of Distortions in Through Hardening of Cylindrical Steel Workpieces by Dimensional Analysis

C. Şimşir, T. Lübben, F. Hoffmann, H.-W. Zoch, M. Wolff:
PREDICTION OF DISTORTIONS IN THROUGH HARDENING OF CYLINDRICAL STEEL WORKPIECES BY DIMENSIONAL ANALYSIS
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New challenges in heat treatment and surface engineering – conference in honour of prof. Božidar Liščić (09 – 12 June 2009, Dubrovnik – Cavtat, Croatia)

ABSTRACT:
Former investigations on the dimensional changes during transformation-free gas nozzle field quenching of cylindrical workpieces exhibited a typical behavior which can be described by few dimensionless numbers [1-3]. Recently, in the outlook of [3], it was proposed to extend the previous approach to the case with martensitic transformation. In this article, an application of this extension to through hardening process of long steel cylinders is presented. The significance of Biot number is demonstrated by computer simulations performed on commercial FEA software SYSWELD. The simulations were verified experimentally for gas nozzle field quenching of 100Cr6 steel cylinders. Results indicate that Biot number based on the thermal conductivity of austenite may be used as a measure of distortion in combination with other dimensionless numbers.


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