Speaker
Description
The global demand for heavy-gauge steel plates for infrastructure, wind-tower and line-pipe applications has increased in recent years, and this change in the consumption behavior intensified productivity challenges in rolling mills, particularly when conventional manufacturing strategies are not adapted to the evolving requirements and dimensions. Productivity in hot rolling is usually driven by the interaction between temperature evolution, recrystallization behavior, microstructural control and mill equipment or dimensional constraints. Niobium microalloying plays a key role in expanding the thermomechanical processing window by increasing critical temperatures associated with austenite recrystallization control (RLT and RST), enabling higher rolling temperatures and shorter holding times between rolling stages. In this work, a modeling-based approach combining niobium metallurgy and temperature–microstructure analysis is presented, using the MicroSim® framework, to finetune alloying and process strategies, including through-thickness plate temperature evolution and rolling pass design, targeting controlled final microstructure distribution. The model couples through-thickness temperature evolution, austenite grain size distribution–based evolution, precipitation behavior, allowing a detailed examination of the alloy design and rolling schedule strategy on microstructure, being able to adjust the process efficiency with reduced holding times and transfer bar thickness between rolling stages. Productivity-oriented simulation scenarios were evaluated, focusing on cost-effective thermo-mechanical process of heavy gauge products. The results indicate that productivity improvements can be selectively achieved through incremental niobium additions when combined with a detailed, through thickness definition of temperature and strain evolution, enabling reduced holding times and higher finishing temperatures without compromising microstructural homogeneity, highlighting the importance of holistic design of composition and processing parameters as key lever towards production excellence.