Open Access Conference Proceedings

The main disadvantage of using classical (butt) oval roll groove in the oval-round roll pass schedule is the relatively small coefficient of elongation. This fact requires a larger number of passes to achieve the final dimension of the bar (or wire). This may be a problem for a rolling mill with fewer stands. The coefficient of elongation can be increased by reducing the distance between the rolls. However, we are facing problems with the arising of the flash in the second (round) groove. A possible solution is to use an elliptical oval groove in the first pass which causes greater elongation in the round groove. This paper deals with the computer simulation of hot bars rolling in two consecutive passes in the oval-round roll pass schedule by FORGE. The initial and boundary conditions of the FE analysis was validated and verified by a laboratory hot rolling of round steel bars on flat and round grooved rolls at different rolling temperatures. We compared the rolling forces and the rolled shapes after the individual passes. In this paper the different settings of butt and elliptical ovals and their impact on the overall coefficient of elongation in both passes are presented. Our results showed that the use of an elliptical groove can greatly improve the overall coefficient of elongation.

Keywords: Hot bars rolling, roll pass schedule, FE analysis, coefficient of elongation

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