Table of Contents

• 40

• An Examination of the Underlying Physics and Mechanics of Herringbone and Diagonal/Cross-Buckle Flatness Distortions — Part 1: Basic Principles and Organization of Analysis

  Herringbone and diagonal wrinkles/cross-buckles are related members of a family of non-trivial, visually stunning and terribly confounding flatness defects. This family encompasses a spectrum of cascading complexity, ranging from relatively simple, full-width diagonal wrinkles to several varieties of multi-facetted, high-fidelity cross-hatch patterns. Gaining an understanding of how all this works, how these defects form and what can be done about them is an involved discussion. This article starts things off by introducing the key concepts and then examining a case study concerning the most basic family member: diagonal wrinkles/buckles.

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• 54

• Successful Operation of an Anti-Chatter Solution at ArcelorMittal Dofasco’s Tandem Cold Mill

  Primetals Technologies has developed a unique anti-chatter system to eliminate third-octave mill chatter. It represents a high-dynamic hydraulic solution that introduces damping and stabilizes the rolling process. The first permanent industrial application of this technology, called ChatterBlock Expert, is in operation at the coupled pickling line tandem cold rolling mill (CPCM No. 1) of ArcelorMittal Dofasco in Canada. It demonstrates that it can effectively suppress thirdoctave mill chatter vibrations and that chatter-critical products can now be rolled at significantly higher rolling speeds without any quality degradation. The industrial solution and results from its operation will be presented in the article.
   

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• 60

• Aspects of Boundary Lubrication in Advanced High-Strength Steel Rolling

  Boundary lubrication is important in controlling roll forces in cold rolling. Friction is reduced by molecule adsorption, and local adhesion is minimized by chemical reactions at the contacting surfaces. Pilot mill trials on advanced high-strength steel and a softer steel type showed clear differences in roll force between lubricant emulsions. The coefficient of friction in these trials was analyzed and it was shown that it may include contributions of elasto-hydrodynamic lubrication, micro-plastohydrodynamic lubrication, sliding boundary friction and unprotected friction. The lubricant performance was shown to be mainly governed by surface protection and film formation. The method assists lubricant development based on an understanding of lubrication mechanisms.

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• 72

• Improving Combustion Heating Energy and Emissions Via Retrofit Ceramic Inserts

  Steel reheating in continuous annealing lines often relies on radiant tube combustion. This article will review benefits of retrofit ceramic technologies and their application to industrial radiant tube heating. Such technologies reduce energy consumption and CO2 emissions by up to 30% while substantially lowering NOx emissions versus conventional installations. Modern retrofit ceramic devices feature twisted tapes, twisted channels and other designs tailored to enhance combustion. Through illustrative case studies, this article will summarize how advanced combustion modeling combined with industrial ceramic forming technologies provide high-performance solutions for managing flame efficiency and emissions.