Tandem Cold Mill

TANDEM COLD MILL

Tandem cold-mill solutions from Primetals Technologies stand for high product yields combined with flexible production, low operational costs and simplified maintenance work.

Depending on the product mix, the production capacity of continuous tandem mills from Primetals Technologies can exceed 1.2 million tons per year. The goal is to provide solutions that offer maximum added value for customers. Advanced mill stand actuators contribute to improved yield, user-friendly mill operation, and high-quality strip that lies within the specified tolerance values. Both 6-high and 4-high mill stands with their specific features and benefits are supplied on the basis of detailed analyses of product and customer requirements.


Benefits

By joining coils prior to entering the mill, a continuous tandem cold mill results in additional benefits such as:

  • Highest production rates
  • Optimized yield
  • Reduced roll consumption
  • Flexible production
  • Tight tolerances for strip thickness, shape, and high surface quality
  • Low costs for operation, maintenance, and minimum down times
  • Fewer operators
  • Reduction in off-gauge material
  • Elimination of strip threading problems
     

Features

The Tandem mill consists of three to six mill stands arranged in series to progressively reduce the thickness of the strip in a single pass. A continuous tandem mill has a welder and accumulator looper at the entry end to join successive coils of pickled hot rolled material. This provides a large-scale mill that is capable of full automation to deliver the most advanced levels of quality and operating stability. It provides high production efficiency, and is used in the production of a broad range of steel types, from general construction materials to high-grade materials for automobile panels and other purposes.

Increasingly, for automotive steels, high-tensile materials at thinner gauges are being demanded to save vehicle weight and hence improve fuel consumption. As a result, higher performance is being demanded of the rolling mills. To meet this need, a continuous 5-stand tandem mill directly connected to the pickling line and using 6Hi UCM-Mill (Universal Crown Control mills) for all stands has become the standard.

The UCM-Mill features:

  • Work roll bending
  • Intermediate roll bending
  • Intermediate roll shifting
  • Super heavy reduction
  • High strip shape control
  • Stable operation
  • Roll inventory reduction
  • Yield increase (by decreasing edge drop of the strip)
     

To cope with the high speed of delivery of the rolled strip a carrousel tension reel coils the strip on exiting the mill. This has two mandrels enabling the strip to be cropped on completion of a coil allowing the second mandrel to accept the oncoming strip without stopping the mill.  
 


Plant productivity and product quality are substantially depending on the quality of plant automation, process control, and available process optimization functions.

To get the best performance out of a plant, Primetals Technologies provides add-on specific optimization solutions for further improvement of production efficiency and strip quality, besides standardized high performance automation system. 
 

Throughput maximization with:

  • OGO - Off Gauge Optimization for integrated rolling process
  • SOS - Speed Optimization System for throughput optimization 
     

Excellent Strip quality with:

  • REC - Roll Eccentricity Compensation for uniform and accurate strip thickness
  • CECO - Coil Eccentricity Compensation for uniform and accurate strip thickness
  • AFC - Model based Automatic Flatness control
  • ChatterMon / Mill Chatter Monitoring with automatic process speed adaptation
     

Production flexibility and special steel grades:

  • Precise mill setup by high-sophisticated Rolling models complying with changing production requirements and high strength steel qualities
  • Neural network based adaptation and setups promising high product flexibility and easy extension of the production to new materials
  • Optimized weld seam rolling supporting flexible production and obtaining minimum off-gauge

Integrated Plants & Solutions for tandem cold mill — Experience that Matters

Please follow the corresponding links to learn more about our competences:

    

Reference Story

TCM for Thin Gauge and High Speed Rolling

Customer:
Posco-Vietnam PL-TCM (TCM Section) / Phu My, Vietnam

Main Specification: 
Material: Low Carbon Steel, High Strength Steel
Strip Thickness: Entry 1.8 to 5.0 mm, Delivery 0.15 to 1.6 mm (For Construction)
Strip Width: 700 to 1,570 mm
Coil Weight: Max. 35,000 kg
Rolling Speed: Max. 1,700 m/min
Mill Type: 6Hi UCM-Mill (No.1 to 5 Stand)