Conversion of a Continuous Tandem Line to a Pickling Tandem Line at voestalpine

Pickling tandem line (tandem to the left, strip running area at center, and inlet to the right) in cold rolling mill No. 3 at voestalpine's plant in Linz, Austria.

voestalpine Stahl will convert its existing continuous tandem line at its steel plant in Linz, Austria, into a pickling tandem line with Primetals Technologies. A new fully automated pickling tandem line in cold rolling mill No. 3 will increase the production quality of high-strength and ultra-high-strength steel grades for the automotive, household appliance, and construction industries, not to mention electrical steel grades e-mobility among other sectors as well. The plant is designed to produce approximately 1.9 million tons of steel per year and will utilize state-of-the-art digitalization solutions for fully automated operations. A new pickling and trimming section will complete the conversion of the continuous tandem line at cold rolling mill No. 3, including a newly supplied strip running section with essential process machinery.

Optimized Layout

The conversion of the existing entry area for hot-rolled material will occur during regular operating and maintenance procedures to minimize downtime. A current control roll in front of the new scale breaker will serve as a switch between the existing and the new strip running area. This layout allows the building of new plant sections while simultaneously operating the tandem mill and quick integration of new plant sections.

Improved Quality and Thickness Tolerances

The existing entry area will include a coil preparation system, a scrap removal system, and a new anti-coil break roll. The bend straightener improves the flatness of the incoming hot strip and increases the pickling effect by scaling up to a maximum speed of 270 meters per minute. The trimming shear section includes a turret-type side trimmer, inductive edge heating, and edge and strip inspection devices, which can operate at speeds of 380 meters per minute. Edge heating supports trouble-free trimming. The existing five-stand 4-high tandem cold rolling mill reaches a maximum speed of 1,000 meters per minute. A new thickness gauge behind stand No. 3 completes the already optimized instrumentation and, in combination with new controllers, enables the strip thickness tolerances to be improved.

Automation and Digitalization Upgrades

The project scope includes a comprehensive upgrade of the electrics and automation systems for cold rolling mill No. 3 and an update of the existing multi-processor control system. The replacement of control devices, electronics, and safety switchgears will be vital to optimizing the new pickling tandem line. In addition, higher-level functions will migrate to the latest programmable logic controllers, and further upgrades of operating systems, Level 1 device libraries, and Level 2 process models ensure immediate operational improvements. At the same time, automation will handle the simultaneous operation of the existing and new plant configurations. The electrics and automation solutions will integrate into the existing plant for strip guiding of the new pickling line. Additional automation functions are available for the programmable logic controllers, such as strip scale breaker control, trimming shear, S-blocks, accumulators, extensive strip inspection functions, tension control, and strip guiding. The pickling section is connected via a level 2 interface and is integrated into the standard operator interface.