METALLURGiCAL RESEARCH THROUGH IMPLEMENTATION: A NEW TECHNOLOGY FOR SUSTAINABLE PRODUCTION OF SUPERIOR QUALITY HOT ROLLED COIL

摘要

The microstructural phenomena of recovery, recrystallization, precipitation, grain growth and phase transformation during thermomechanical processing of steel, are applied to estimate of final microstructure of steel strips, produced through hot rolling in a hot strip mill. A set of mathematical models is developed to simulate thèse behaviors and the final microstructure, and to assess the mechanical properties therefrom. The aim to develop a suitable technology to control the product properties during actual processing stage itself, and that too over the whole length of a coil, rather than post-production product-testing stage for a single sample from one end of coil (as practiced Worldwide today). Thus, the new technology exploits the 'advanced microstructural engineering' to provide solution for a problem the world faces today -how to maintain uniform mechanical properties over the entire length of a coil, especially important for microalloying grades used for gas pipelines and automotive applications. An innovative approach is undertaken to combine the above set of physical metallurgical models with a data driven Artificial Neural Network Model to include process uncertainties into the final assessment of mechanical properties. Danieli CQE (Coil Quality Estimator), based this approach, was implemented in the United Metallurgical Company (OMK), at Vyksa, Russia - one of the largest pipe manufacturers of oil and gas pipelines for arctic applications. Danieli CQE ensures uniformity of mechanical property over the length of a coil, and thereby reducing downgrades. The system is applicable for low, medium, high carbon, and microalloying grades. Apart from ensuring superior quality product, it is very useful to identify the appropriate process window for development of new products. It is also useful for process optimization, and to ensure minimum utilization of energy and resources including expensive ferroalloys to produce any given grade of hot rolled coil.