Transformation behaviour of steel in the in-line hot rolling steel process
The importance of in-line hot deformation processes at European steel companies is continuously increasing. Efficient laboratory test methods are not available for a thorough simulation of casting and in-line rolling with subsequent cooling. Microstructure and mechanical properties of directly rolled products are different from those conventionally produced (cooling and reheating prior to rolling) because of different initial austenite grain size, fraction and distribution of precipitations before and after the gamma-alpha transformation. In this project a novel deformation dilatometer (NDD) was designed and constructed for the simulation of direct rolling processes. Its design is based on a parameter study on which technologies are required and what parameters are decisive for an adequate small-scale simulation of direct rolling. An important conclusion from the tests with reheated and remelted samples was that the transformation behaviour of remelted samples is different from reheated samples, even if the austenite grain size is similar for both conditions. The NDD allows for remelting samples. From a review of the available modern laboratory techniques a contact-free measurement of length changes was selected to detect phase transformations by the shadowed light method and modified for employment in the NDD. Based on the parameter study the NDD will enable an improved small-scale simulation of direct rolling processes by allowing a high strain, high strain rates, short interpass times and high cooling or quenching rates.
Bibliographic Reference: EUR 22564 EN (2007), 139 pp. Euro: 25
Availability: Katalogue Number: KI-NA-22564-EN-S The paper version can be ordered online and the PDF version downloaded at: http://bookshop.europa.eu
ISBN: ISBN: 978-92-79-04996-5
Record Number: 200719257 / Last updated on: 2007-07-05
Original language: en
Available languages: en