Upgrading existing plate mills for higher strength product

Abstract

Older plate-making mills face a real challenge from the trend towards higher strength. Plate mills make an excellent case study for the issues in upgrading mills generally. The forces generated in plate rolling are extreme, as are the demands placed on the equipment and its process control. It is not only the strength increase that compromises older plant, however. A whole range of applications quality standards go along with the exploitation of the additional strength of modern steel grades. The challenge, therefore, is not limited to increasing the power, torque and load limits of the mill stand; ancillary process areas sometimes generate the best return in a modernisation project. Common examples include improvements in post-rolling cooling, levelling and shear-line operations. The potential of state-of-the-art automation, including model-based control, of the plate mill is also discussed. The steel industry is not very sympathetic towards yesterday's plant designers, often blaming them for assets that underperform when processing new steel grades. But is today's generation of plant designers doing any better? In conclusion, we ask whether, in the long view, the aim should be to develop the future-proofed plate mill, and what such a mill might look like.