AISTech 2022

Fundamentals for Developing Nanoprecipitation-Strengthened Thick-Gauge HSLA 550 Steel Through a Flex CSP Mill (Room 316)

16 May 22
10:30 AM - 11:00 AM

Tracks: Continuous Casting/Metallurgy-Steelmaking & Casting

Speaker(s): C. M. Enloe, CBMM North America Inc.; V.S.Y. Injeti, Plant Metallurgist, Big River Steel, a U. S. Steel Company; Amar De, Big River Steel – A U. S. Steel Co.; Venkata Natarajan, Plant Metallurgist, Big River Steel; Chirag Mahimkar, Big River Steel - A U. S. Steel Co.; Aaron Meyer, Hot Mill Electrical Maintenance Supervisor , Big River Steel – A U. S. Steel Co.

In continuous strip processing, low tunnel furnace temperature, combined with significantly short residence time, positively modifies the evolution of carbonitride precipitates in austenite and minimizes over coarsening of austenite grains prior to hot rolling. Such operational advantages were utilized in developing lean yet high-performing high-strength, low-alloy (HSLA) 550 steels. A lean, low-carbon base chemistry was adopted for the development of microalloyed HSLA 550 steels up to a thickness of 16 mm. Hot rolling was designed to achieve excellent low-temperature toughness and superior cold bendability suitable for roll-forming operations. Ti or Ti+Nb additions were appropriately chosen for grain refinement and significant nanoprecipitation strengthening.