Coupled pickling line and tandem cold mill

High-capacity production for high-quality products

Pickling lines and tandem cold mills

For a wide range of product applications, the required strip thickness, flatness, and surface quality can be achieved more economically by linking the pickling and cold rolling processes. This delivers significant improvements with regard to mill productivity, yield, and production cost savings as a result of the elimination of strip threading and tailing-out operations. Reduced strip-head and tail-end losses also contribute to better overall yield. Our speed optimization system ensures maximum throughput rates under all operating conditions and maintenance, roll consumption, and manpower requirements are lowered. Typical production capacities of such combined facilities are in the range of 1.2-2 million t/a.

Pickling lines supplied by Siemens Metals Technologies are characterized by high pickling rates, low-cost pickling operations, flexible production, a wide range of product sizes, qualities, reliable plant operation, and low maintenance requirements, as well as compliance of the highest standards for environmental safety.

Main benefits of Siemens Metals Technologies' coupled pickling lines and tandem cold mills:

  • Highest pickling throughput rates

  • Uniformly pickled surfaces

  • Closed loops of acid, fume, and rinse circulation reduce operating costs in an environmentally friendly manner

Selected references:

  • SAIL Bokaro Steel Plant, Jharkand, India

  • Wuhan Iron & Steel, Wuhan, China

  • Corus, IJmuiden, Netherlands

  • Liuzhou ISCO, Liuzhou, China

  • ArcelorMittal, Mardyck, France

  • Tangshan Iron & Steel, Tangshan, China

  • Benxi Iron & Steel, Benxi, China

  • Panzhihua, Panzhihua, China

  • voestalpine Stahl, Linz, Austria

  • ArcelorMittal, Sparrows Point, MD/USA

  • ArcelorMittal, Ferblatil, Belgium

  • Ilva, Taranto, Italy

  • Corus, Port Talbot, UK

  • Angang, Anshan, China

Technical features:

  • SIROLL Smartcrown contour roll associated with axial roll-shifting for enhanced flatness control

  • 4-high and 6-high mill stands for high mill flexibility for all products

  • Morgoil bearings or roller bearings depending on application

  • Physical-based analytical online models supported by neural networks ensure accurate mill setup to achieve tight tolerances right from the start

  • Flexible thread-in and thread-out strategies for all kinds of materials, such as high-strength steel grades

  • Patented compensation systems for correcting periodic roll and coil eccentricities

  • Use of last stand in temper mode for smoothing or roughing strip surface

  • Fully automatic operation allows operators to concentrate on product quality; actual operator intervention is reduced to an absolute minimum


Strip Pickling

Cold Rolling - Strip Pickling

Improved performance for continuous pickling lines

Continuous pickling lines supplied by Siemens Metals Technologies feature modular design, high pickling efficiency, economical operation, and the application of advanced technologies such as turbulence pickling. The main benefits include reliable strip threading, increased pickling speed, homogeneous descaling of strip, reduced steam consumption, and elimination of strip staining.


Controlled Elongation Machines

Cold Rolling - Controlled Elongation Machines

Controlled Elongation System for SIROLL PL processing lines

Siemens Metals Technologies has been a leader in the development of Controlled Elongation Machines (CEM) since 1953. Our CEMs meet all crucial success metrics and are supported by numerous patents. The result: higher performance, increased reliability, and better adaptability to innovations in steel production. Direct elongation control permits steel producers to process metal strip with yield point and tensile strength close to each other, without the risk of strip breakage.


SIROLL Active Chatter Damping

Cold Rolling - SIROLL Active Chatter Damping

SIROLL CM Active Chatter Damping – eliminating third-octave chatter in tandem mills

The SIROLL CM Active Chatter Damping system eliminates chatter completely within a mill’s operating range, thus, making it possible to run a tandem mill at its full limits without third-octave chatter. The active chatter damping system is designed as a completely integrated mechatronic solution.


Upgrading pickling process section

Siemens Metals Technologies offers a modular system for the upgrade of pickling lines.

Siemens Metals Technologies has vast experience in upgrading, modernizing and coupling pickling lines and tandem cold mills. Following a systematic and modular approach, we develop a modernization plan based on our customers’ individual needs, taking all peripheral conditions into account. Our upgrade modules for pickling lines (coupled to tandem cold mills) increase plant availability and production yield, reduce operational costs, ensure uniform finished surface quality and closed loops of acid, fume and rinse circulation, thus reducing operation costs in an environmentally friendly manner.


Drive train package for cold mills

When it comes to final strip quality, the performance of a multi-stand mill depends greatly on the main drives.

The Siemens Metals Technologies drive train package comprises all mechanical, electrical and automation components for the drive train. It includes medium-voltage power supply and harmonic filters (if required), a drive transformer, drive system (Sinamics), motor and switchgear, sensors and brakes, reducer or pinion gear, couplings, spindles, and torque limiters. The drive train package leads to improvement of production throughputs, high plant availability and low operating costs. With this package producers benefit from a single supplier for mechanical, electrical and automation systems, and are assured consistent component quality.


Scale breaker for cold rolling mills

Siemens Metals Technologies' scale breakers ensure improved surface quality and line productivity, as well as reduced production costs.

Siemens Metals Technologies has developed a new generation of scale breakers. These have a compact design, are easily installed, require minimal line shutdown to replace a scale breaker, and supports quick operation spares changing (cassettes), low energy consumption, and low maintenance costs. The new generation of scale breakers increases the breaking of scale at the strip surface and allows a better acid attack in the pickling section. Moreover, our highly efficient scale exhaust system avoids dust emission through complete hooding of the stand.


Safety package for cold-rolling mills

Siemens Metals Technologies offers safety concepts for new and modernized rolling mills, as well as safety studies and upgrades.

The Siemens Metals Technologies safety package provides maximum risk reduction by conducting in-depth and comprehensive analysis of the safety, functionality, usability and cost factors associated with all plant machinery. Based on the information gained, Siemens compiles a safety plan that specifies each machine’s limits and intended use, identifies potential hazards, estimates the risk associated with each hazard , and eliminates the hazard or reduces the risk through the implementation of protective measures. The safety package offers support for safe working methods and workplaces as well as reducing conversion costs.



Welders

Cold Rolling - Welders

Welders from Siemens Metals Technologies – the optimum solution for every situation

Siemens Metals Technologies supplies a range of welders to handle the tough requirements of coupled pickling tandem mills and continuous tandem cold mills: mash lap welders for efficient strip joining, flash butt welders for superb reliability in demanding welding tasks, and laser welders for top quality with minimum maintenance.


Upgrading to continuous tandem cold mills and linking pickling and cold-rolling processes

Siemens Metals Technologies offers efficient and modern solutions for pickling sections coupled to tandem cold mills.

By converting a batch-type tandem cold-rolling mill into a continuous tandem cold mill while linking the pickling and cold-rolling processes, producers can improve production rates, product quality, dimensions and yield, facilitate easier operation and maintenance, achieve energy savings and, most importantly, lower overall costs. Production capacity can be increased from approximately 700,000 to 1.2 million t/a by upgrading to continuous operation. By linking the pickling and cold-rolling processes, typical production capacities can be further increased to 2.0 million t/a.


Flatness quality package for cold mills

The Siemens Metals Technologies flatness quality package offers solutions to add, replace or enhance shape control systems in all kinds of cold rolling mills.

Siemens Metals Technologies' quality improvement packages are suitable both for incremental improvements and major modernization processes. Depending on the mill type the mill stands are equipped with roll bending or shifting systems, SIROLL SmartCrown roll contour or multizone cooling. The backbone of the flatness quality package is the patented SmartCrown roll contour, which can be applied to work and/or intermediate rolls. Benefits include significantly enhanced control range, replacement of all conventional roll contours with a single roll contour, control architecture that meets current and future requirements, more flexible pass schedule due to the large adjustment range of the SmartCrown rolls, and savings in roll inventory.


Roll-change system for cold mills

The Siemens Metals Technologies roll-change system increases mill availability and eliminates roll damage, thereby ensuring a significant increase in production.

Many plant owners still change work rolls manually, which is rather time-consuming.By replacing this system with the Siemens Metals Technologies automatic roll-change system mill availability can be significantly increased. Our automatic roll-change system allows fully automatic work-roll change with or without strip in the mill. The roll change can be carried out for each mill stand individually or for all stands together. This system can be applied to new cold rolling mills as well as modernizations of existing mills. In the event of an upgrade the disturbance to production is kept to a minimum.


Side trimmer & scrap chopper for cold mills

The Siemens Metals Technologies high-precision side trimmers and scrap choppers reduce production costs, increase throughput and improve strip edge quality.

The new generation of side trimmers and scrap choppers is characterized by compact design, easy installation, easy exchange of knives, double knife head, high availability, low maintenance costs and best performance for fast knife and strip width change. Siemens Metals Technologies supplies the dynamic width change (DWA) functionality, allowing the knives to be adjusted to precise degrees. This leads to higher productivity as the strip does not need to be stopped. Special high-precision spindle units are installed for GAP, LAP and width adjustment. This high-precision side trimmer ensures high accuracy of the strip width and top-grade automation movements by the servo-motor.


Strip cleanliness

SIROLL CM high efficient blow-off system to ensure removal of emulsion.

Remaining liquids on the strip impair surface quality during recoiling. A strip blow off system with a special air-nozzle arrangement can be installed to remove any residual emulsion. The nozzles act on the strip surface in a cascaded manner and directly form the interfaces between work roll and strip, work roll and back up roll, and between the intermediate and backup roll in 6-high stands. The liquid removed bay the air blast is captured in an exhaust system. The cleaning system guarantees efficient blow-off at all mill speeds, ensuring highest strip-surface quality after rolling.