Influence of the Rolling Loads on the Stress in the Roll Surface Layer

abstract

English

The roll surface is periodically loaded by thermally and mechanically inducted stresses during the rolling. This leads to thermal fatigue, wear, corrosion and contact fatigue. This paper describes the processes of roll cooling simulation and verification of the structural damage of the roll surface layer with a focus on the influence of the rolling loads. The most critical factor for thermal cracks is a tensile stress which appeared in the roll surface layer in the cooling area. In addition, the load like rolling pressure or shear stress can significantly decrease the product life of roll through the facilitation of the thermal crack forming and propagation to the roll core. Three different loading configurations were created based on the real hot strip mills. These configurations had the same cooling on the roll but they varied in the rolling load. The task can be divided into two parts – structural and thermal analysis. The thermal analysis is calculated first. It produces the thermal load in the roll body over time. The boundary conditions describing the cooling intensity are obtained from the laboratory measurements, from the measurement taken in the rolling mills and from the literature. The optimized cooling design minimizes elastic, in some cases even plastic deformation of the material, and provides sufficient cooling, in order to keep the rolls at a reasonable temperature. The efficiency of cooling was examined on the shape of the stress-strain loop.

rolling, thermal fatigue, rolling loads, ANSYS, FEA

ZAHRADNÍK, R.; HRABOVSKÝ, J.; RAUDENSKÝ, M.

17. 10. 2012

Insitute of Metals and Technology

Ljubljana

978-961-92518-5-0

20th jubilee conference on materials and technology. Program and book of abstracts

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20

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http://konferenca2012.imt.si/fileadmin/dokumenti/20.konferenca/Book_of_abstracts.pdf