1. TOPOCROM ® – Texturing: Technology and Advantages Thomas Routschek Salzgitter Flachstahl GmbH, Salzgitter (Germany) Karl Müll TOPOCROM Systems AG, Weinfelden (Switzerland ) BAOSTEEL BAC 2013, Shanghai (China)

2.  TOPOCROM ® - Electroplating Technology ◄◄◄  Demands of the automotive industry on the surface structure of cold rolled sheet metal  Requirements of the steelmaking industry for texturing technology of working rolls for skin passing mills  PRETEX Surface Structure: Prospects Structure of Presentation

3. TOPOCROM ® - Electroplating Technology TOPOCROM ® is a patented Process Technology for Electroplating of Hard Chromium Coatings with a typical hemispherical Surface Structure

4. ++ Texturing of Working Rolls: Comparison of Technologies TOPOCROM – Technology ++ _ SBT + HCr EDT + HCr EBT + HCr SBT EDT EBT TOPOCROM

5. TOPOCROM plating reactor

6. Layout of TOPOCROM - 2 reactor plant (schematically)

7. TOPOCROM Facility for Steel Works POSCO, Gwangyang/South Korea Startup in 2009 Salzgitter Flachstahl, Salzgitter/Germany Startup in 1996

8. Difference between conventional texturing technologies and TOPOCROM Texturing SBT EDT EBT TOPOCROM Idea: Structure for Texturing will be build up on the top of the ground Roll Body by the special TOPOCROM Hard Chromium Electroplating Process  Convex Texture Roll Body Conventional Texturing Technology: Structure will be build mechanically or physically into the surface of the Roll Body  Concave Texture

9. Important Features of TOPOCROM ® - Texturing Important Features of TOPOCROM Coatings  Hemispherical Surface Structure with perfect stochastic Distribution  Adjustable Roughness and Pc Values: Ra ≥ 0,5 µm to Ra ≤ 12 µm  High Peak Account Values also together with high roughness values  Adjustable Topography: open to closed Structure  Hardness comparable with normal Hard Chromium Coatings

10. Variability of TOPOCROM ® - Topography: Open to closed structure Closed TOPOCROM – Structure Open TOPOCROM - Structure Adjustable surface topography with TOPOCROM ® - Texturing openclosed

11. TOPOCROM Texturing: Ra/Pc - values

12. Adjustable calotte - density of PRETEX surface structure

13. High amount of lubricant pockets with ideal stochastic distribution Closed voids Open voids Material face Sheet Forming tool

14. Advantages of PRETEX surface structure The PRETEX – structure of Salzgitter AG provides unique advantages with all surfaces:  Adjustable density of calottes  Precisely distributed hydrostatic lubrication pockets for improved formability  Ideal stochastic distribution of the lubrication pockets  Customized of roughness and peak account  Unique solution for combining low roughness with high peak accounts

15. Structure of Presentation  TOPOCROM ® - Electroplating Technology  Demands of the automotive industry on the surface structure ◄◄◄ of cold rolled sheet metal  Requirements of the steelmaking industry for texturing technology of working rolls for skin passing mills  PRETEX Surface Structure: Prospects

16. Increasing demands of the automotive industry on the sheet metal surface structure Actual and future demands of the automotive industry on the sheet metal surface structure  Improved appearance of painted metal sheet surfaces  Cost saving with paint systems without filler  Improved formability  Very low abrasion in the forming tool  Stable surface characteristics along the entire strip width and length

17. Demands of the automotive industry on the surface structure of cold - rolled sheet metal Requirements for the forming process High mean roughness values High number of lubrication pockets Even distribution of lubrication pockets Homogeneous friction conditions Requirements for painting Low mean roughness values High number of peak account values Homogenous peak distribution Absolutely stochastic roughness distribution (Avoidance of Moirè-effects) Less short- and longwave structures (Avoidance of Orange peel) Paint adhesion and spreading characteristics The fine surface structure is applied to the sheet metal surface by skin passing

18. Actual and future requirements of automotive industry for surface structure of sheet metal: Appearance of painted metal sheet surfaces Requirements for paint appearance  Avoiding of Moire΄ – effects  Avoiding of orange peel Short and Long – Wave Comparison of PRETEX with alternative texturing on galvanized steel sheets Advantages of PRETEX  Fine surface structure with high peak accounts and low roughness  Absolutely stochastic distribution  Low wave-scan values

19. Actual and future surface – requirements of automotive industry for painting applications: Cost saving with paint systems without filler Important factor for surface structure of sheet metall  low waviness Filler and base coat are leveling the substrate, but are superposing the cathodic dip coat with a new waviness profile Cathodic dip coat is filtering the roughness characteristic, but waviness will be transferred  The capability for leveling the waviness will be reduced by saving the filler Challenge for Painting Process Reduction of production costs, energy demand and CO 2 – emission Reduction of painting and drying steps  Saving the filler

20. Actual and future surface – requirements of automotive industry for painting applications: Cost saving with paint systems without filler Painting Process 2010: Paint System without filler Standard VW – Group TL 218 (May 2012) PRETEX is the ideal sheet surface structure for paint systems without filler

21. FEA-Simulation of different friction conditions Conclusions: l PRETEX leads to a better formability l PRETEX leads to a safer forming process Lower stresses and more reserve to FLCwith PRETEX good draw-in with Pretex PRETEX (µ=0,088 ) EDT (µ=0,109) draw-in 25.8 mm draw-in 26.7 mm Actual and future requirements of automotive industry for surface structure of sheet metal: Improved formability

22. Actual and future requirements of automotive industry for surface structure of sheet metal: Improved formability  Previously used: DC06 + ZE 75/75 with EDT – Texturing  Replaced by: DC05 (mod.) + ZE 75/75 BPO with PRETEX – Texturing and Prephosphating  Cost benefit by changing from DC06 to DC05  Reduction of cold welding due to the lower friction coefficient of PRETEX + Phosphating Car Wing

23. Actual and future requirements of automotive industry for surface structure of sheet metal: Less abrasion in the forming tool  Previously used: DC05 with SBT – Texturing  Replaced by: DC05 with PRETEX – Texturing  Cost neutral in steel price  30% reducing of lubrication volume  Reduced cleaning work before cathodic dip coating Body-contoured seat

24. Structure of Presentation  TOPOCROM ® - Electroplating Technology  Demands of the automotive industry on the surface structure of cold rolled sheet metal  Requirements of the steelmaking industry for texturing technology ◄◄◄ of working rolls for skin passing mills  PRETEX Surface Structure: Prospects

25. Actual challenge for the texturing technology Requirements of the steelmaking industry for texturing technology of working rolls for skin passing mills  Characteristic and properties of roll texture  Cost-efficient process for texturing of working rolls  Lifetime of textured working rolls in production  Schedule free rolling Production of sheet metal surface structure

26. Very low Roughness Wear and therefore long Life Time  due to Hemispherical Surface Structure, Multilayer Design and due to the Hardness of Hard Chromium Coatings 3 - 5 times longer Life Time compared to EDT Rolls (+ hard chromium plated) Constant Product Quality with TOPOCROM Rolls from the beginning (no running in-time)  High pressure cleaning of working rolls during operation is necessary Requirements of steel works for working rolls: Life time of working rolls

27. Requirements of steel works for working rolls: Schedule free rolling in HDG – Line № 2 of SZFG

28. TOPOCROM – Texturing Technology: Benefits for Steelmakers Quality advantages for customers regarding formability and paint appearance Customized adjustment of all structure parameters Constant high surface quality of the metal sheets Stable surface characteristics along the entire strip width and length Reliable reproducibility Significant increased Roll Life Time Reduced number of roll changes Remarkable reduction in grinding and texturing costs Increased total service life of the roll and total productivity due to less grinding operations Reduction of roll inventory Higher productivity Reduced costs High wear resistance of TOPOCROM – Rolls allows Schedule Free Rolling Increased productivity/higher mill availability Reduction of roll inventory Modest technological invest Low capital and manufacturing costs

29. Advantages of PRETEX – Steel Sheet Surface Structure for Forming: Low Friction Coefficient Building of closed Lubricant Pockets High amount of Closed Lubricant Pockets with equal Distribution improves formability and reduces abrasion in forming tools. Customized surface structure/roughness/peak account Advantages for Painting: Perfect Stochastic Distribution (no Moiré – Effect) High Peak Count Values (Pc) together with higher Roughness Values Homogenous Peak Distribution Less Short Wave/Long Wave structures improve painting appearance TOPOCROM structured Sheets: Trade Names  PRETEX ® of Salzgitter AG and POSTEX ® of POSCO TOPOCROM ® - PRETEX Surface Structure: Advantages for the automotive industry

30. Structure of the Presentation  TOPOCROM ® - Electroplating Technology  Demands of the automotive industry on the surface structure of cold rolled sheet metal  Requirements of the steelmaking industry for texturing technology of working rolls for skin passing mills  PRETEX Surface Structure: Prospects ◄◄◄

31. PRETEX Surface Structure: Prospects The automotive industry places increasing demands on painting appearance and processing properties of the delivered thin sheet metal. The TOPOCROM structure offers a high potential of optimization possibilities because of the independent customizability of the different structure parameters. In comparison to other texturing processes the TOPOCROM structure provides unique possibilities regarding the variety of structures. Therefore a steady further development of the surface structures by steelmakers is obligatory. To achieve this Salzgitter Flachstahl is linking process- and structure data. The most important milestones are:  Production accompanied by automated 3D-measurements and automated qualification of roll and sheet surfaces  Development of process methods for TOPOCROM plating on the basis of data mining  Systematic generation of PRETEX structures on thin sheet metal optimized for painting appearance and formability  Cooperation with press and paint shops of leading automotive manufacturers to adjust the results and support production- integration

32. PRETEX Surface Structure – Prospects: Measuring Data  Automated measurement of 27 surface-samples within 45 min  Autonomous recognition and evaluation of calottes  Calculation of structure parameters by a mathematical alghorithm

33. PRETEX Surface Structure – Prospects: Database, Datamining Linking of production data: Communication between Topocrom-Structure-Database and other production systems including surface inspection. Datamining: Evaluation of structural parameters to minimize imprints caused by dirt adhesions on work rolls.

34. Laser Optical Profile Filter Longwave (LW) 0,6-10mm Shortwave (SW) 0,1-0,6mm Substrat ca.110 GE (bei 20°) PRETEX Surface Structure – Prospects: Optimization for press and paint shop  Laboratory trials for better formability and paint appearance  Optimization of structure parameters in close cooperation with automotive manufacturers  Integration of Pretex-Technology into production processes and creation of new products

35. TOPOCROM ® – Texturing: Technology and Advantages Thomas Routschek Salzgitter Flachstahl, Salzgitter (Germany) Karl Müll TOPOCROM Systems AG, Weinfelden (Switzerland ) BAOSTEEL BAC 2013, Shanghai (China)