Title: The influence of geometrical features on rewetting behaviour of cylindrical components

Authors: Friedhelm Frerichs; Thomas Lübben

Addresses: Stiftung Institut fuer Werkstofftechnik, Badgasteiner Straße 3, D-28359 Bremen, Germany. ' Stiftung Institut fuer Werkstofftechnik, Badgasteiner Straße 3, D-28359 Bremen, Germany

Abstract: During immersion quenching the transition from film to nucleate boiling - the rewetting of the sample surface - is a complex process which leads to extreme local changes of the heat transfer coefficient. The start of the rewetting process depends on specific geometrical features like edges, boreholes, couplings, etc. From these starting points the rewetting front moves forward. The present paper investigates the influence of geometrical properties on the starting of rewetting and the movement of the rewetting front across the work piece. Cylinders made out of stainless steel with different edge shapes, lengths, and diameters will be considered. The edge configuration varies in a few steps from chamfered edges to spherical formed edges. The quenching was done with high speed oil (Isorapid 277®). The aim of the paper is the gathering of information of the local and time dependent HTC necessary for heat treatment simulations.

Keywords: heat treatment; simulation; boundary conditions; immersion quenching; high speed oil; Leidenfrost phenomena; rewetting behaviour; geometrical features; cylindrical components; heat transfer coefficients; stainless steel cylinders.

DOI: 10.1504/IJMMP.2012.047495

International Journal of Microstructure and Materials Properties, 2012 Vol.7 No.2/3, pp.125 - 142

Published online: 24 Jun 2012 *

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