Title

TRIPLE-A: HIGH SOPHISTICATED ROLLING MODEL WITH SPECIAL EMPHASIS ON ROLLING CONDITIONS IN THE FINAL PASS OF COLD AND TEMPER ROLLING MILLS

TRIPLE-A: HIGH SOPHISTICATED ROLLING MODEL WITH SPECIAL EMPHASIS ON ROLLING CONDITIONS IN THE FINAL PASS OF COLD AND TEMPER ROLLING MILLS

Authorship

Krimpelstaetter, Konrad

Krimpelstaetter, Konrad

I am this author

DOI

10.5151/2594-5297-22546

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Abstract

The final pass any cold rolling mill is typically characterized by reduced relative and absolute strip thickness reduction, small strip thickness, raised material strength due to work-hardening in the previous deformation steps, often in combination with application of rough work rolls (to adjust the strip surface topology). These process conditions can lead to severe work roll flattening and in extreme cases to practical limitations of the reduction capability and the achievable final product thickness (rollability). The (theoretical) rollability limit is reached if the strip thickness does not decrease anymore although the work rolls are adjusted more and more against each other resulting in extreme work roll flattening. Siemens VAI’s TRIPLE-A cold rolling model was developed for offline calculations in order to predict rolling forces and rolling torques very accurately over a wide range of applications covering the trend to very thin and hard strips as well as rolling scenarios in the final pass of any kind of cold rolling and temper rolling mill. The new high sophisticated simulation model ensures an improved modeling of rolling, as the circumferential work roll displacements allow for the existence of slip- as well as no-slip-zones inside the roll bite. The formation of a neutral zone, where the roll tangential speed matches the strip speed, instead of a neutral point is a consequence of this approach. Furthermore, the model offers the big benefit that the “rollability” and reduction capability can be determined very accurately compared to existing cold rolling models. Triple-A was calibrated against practical data from industrial cold rolling mills. Excellent agreement between measured and predicted rolling forces and rolling torques prove the validity and quality of the developed model. Therefore Triple-A represents a strongly improved tool for the dimensioning of cold rolling mills.

The final pass any cold rolling mill is typically characterized by reduced relative and absolute strip thickness reduction, small strip thickness, raised material strength due to work-hardening in the previous deformation steps, often in combination with application of rough work rolls (to adjust the strip surface topology). These process conditions can lead to severe work roll flattening and in extreme cases to practical limitations of the reduction capability and the achievable final product thickness (rollability). The (theoretical) rollability limit is reached if the strip thickness does not decrease anymore although the work rolls are adjusted more and more against each other resulting in extreme work roll flattening. Siemens VAI’s TRIPLE-A cold rolling model was developed for offline calculations in order to predict rolling forces and rolling torques very accurately over a wide range of applications covering the trend to very thin and hard strips as well as rolling scenarios in the final pass of any kind of cold rolling and temper rolling mill. The new high sophisticated simulation model ensures an improved modeling of rolling, as the circumferential work roll displacements allow for the existence of slip- as well as no-slip-zones inside the roll bite. The formation of a neutral zone, where the roll tangential speed matches the strip speed, instead of a neutral point is a consequence of this approach. Furthermore, the model offers the big benefit that the “rollability” and reduction capability can be determined very accurately compared to existing cold rolling models. Triple-A was calibrated against practical data from industrial cold rolling mills. Excellent agreement between measured and predicted rolling forces and rolling torques prove the validity and quality of the developed model. Therefore Triple-A represents a strongly improved tool for the dimensioning of cold rolling mills.

Keywords

Cold rolling; Temper and skin-pass rolling; Mathematical model; Rollability; Cold rolling limits; Last rolling pass.

Cold rolling; Temper and skin-pass rolling; Mathematical model; Rollability; Cold rolling limits; Last rolling pass.