Skin-Pass Mill

SKIN-PASS MILL

Excellent Flatness and a Perfect Finish

The advantages of skin-pass mills (also known as temper mills) from Primetals Technologies include full compliance with tight strip elongation tolerances; excellent flatness performance; high surface quality with respect to roughness, peak count and low residuals; and the availability of wet and dry skin-passing modes. Primetals Technologies supplies stand-alone and inline skin-pass mills in either single- or two-stand design for adjusting the final mechanical properties, flatness and surface finish of cold-rolled strip. Due to its higher rolling forces, the 6 high UCM-Mill is the preferred skin-pass mill solution to meet the continually increasing demands placed on strip flatness, elongation and roughness, especially for hard-material grades.


The most common configuration is a single skin-pass mill that rolls in a single direction, with tension reels placed at both ends of the mill. However other types are also used, such as a temper mill with two mill stands for higher tempering in tin-sheet production mills which include DCR (Double Cold Reduction) mills with two or even three mill stands for rolling thin tinned materials known as DR materials. Single or double stand skin-pass mills are placed in-line at the exit of continuous annealing and continuous galvanizing lines. 6 high UCM-MILLs are supplied in response to recent requirements to roll harder material, such as hard tin plate and AHSS, with improved strip flatness control capability.
 

Main benefits of Primetals Technologies' skin-pass mills

  • Tight strip elongation tolerances
  • Excellent flatness performance
  • High surface quality (roughness, peak count, low residuals)
  • Possibility of wet and dry skin-passing modes
  • High speed roll changing
  • 6Hi UCM-MILL
     
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Complete automation and process control for Skin-Pass Mills

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.

Inline Process Quality Insurances

  • Strip defects follow-up with preventive defects passing strategy
  • Accurate roughness and elongation controls
  • Flatness Optimizer - Model based Automatic Flatness control
  • Automatic Coiling tension distribution

Final Product Quality Certification

  • Process data recording
  • Product classification report

Integrated Plant Safety Control System

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TECHNOLOGY AND MODERNIZATION PACKAGES

Get striking results with incremental investments

Roll Eccentricity Expert Elimination of a known strip thickness quality disturbance from rolls
PropertyMon Inline measurement of steel strip properties
TorqueMon Inline measurement of roll spindle torque for rolling mills
Position Transducer Position measurement of rolling mill hydraulic capsule
Upgrade to Double Cold Reduction Mill (DCR) Double cold reduction process for Temper Mill
Modular Coil Shuttle System (MCS) Rail-based, fully automated modular coil transport system

Reference Story: UC-MILL to achieve excellent strip shape for high strength steel without tension leveler

Customer:
Guangzhou JFE Steel Sheet Co., Ltd., China

Type of plant:
In-line Skin-Pass Mill for Continuous Annealing Line to produce HSS for automotive application

Technical Data:
Strip Thickness: 0.30 ~ 2.6 mm
Strip Width : 800 mm~1,880 mm
Mill Type : 6-high UC-MILL

Our solution:
The 6-high UC-MILL was installed to enhance the customer's product portfolio which now includes harder materials up to 1180 MPa HSS. The mill is capable of rolling such high-demand materials in wide width range and into excellent strip shape without tension leveler, to boost the plant's competitiveness.

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