overall technical level to the leading position among the mills of similar type.
Similar systems such as that in EOS [1], after installation, had been under continued improvement in draft scheduling logics, shape control and other related, for over 5 years until 2003. In comparison, NISCO Level 2 is a relatively newer installation, and most of those improvements were not yet done. NISCO did some improvements in user interface, to allow operator to handle many issues, but as to the logic improvement such as that on draft scheduling and shape control, many development projects are still ongoing. Typical example of the logic weaknesses exists in, that when force prediction is getting more accurate, the draft schedule is not improved, rather, sometimes goes worse.
Improvement to the draft schedule logics is not included in the work scope of this force prediction project. However, without this part of improvement, the results of the force prediction cannot be well applied and thus the draft schedule remains to be poor. Therefore, a project parallel to the force prediction has been created and is currently ongoing. The logics for draft scheduling based on predicted force, consists of three steps, taking finishing pass logics as example: (1) initial design of the draft schedule; (2) establishing equation system to examine whether a list of constrains are met; and (3) if one or more constrains cannot be satisfied, creating a schedule based on lowered requirement. Recent diagnoses indicate that modifications to all the three steps are necessary. Good progress has been made in achieving improved draft schedule; however, it is to be discussed in a future paper, beyond this current one.
Shape control through Level 2 consists of a list of sub-projects and is of high economic benefit. Just as in every plate/coil mill, Level 2 modification to optimize plate shape control is to be performed in a variety of areas such as general shape, head/tail end, and surface, etc.
NISCO has made great efforts in controlled rolling, to improve rolled steel properties. Mill management has paid high attention in this field. Due to the fluctuation of the market and narrowed profit margin in current plate/coil production, alloy reduction through increased and stable product properties has been put in high priority. A long list of model improvement measures for increased product properties have been discussed, and consensus has been reached. Since years, Metal Pass has been developing finer Level 2 models and new Level 2 functions (the "next-generation Level 2") [2][3][8], which allows mills to easily apply controlled rolling.