A comparative study of microstructures and mechanical properties obtained by bar and plate rolling

Microstructures and mechanical properties of a low carbon steel were studied after plate rolling and bar rolling. Plate rolling is characterized as a monotonic compressive loading, while bar rolling is characterized as a cross-compressive loading. A four-pass plate rolling and bar rolling experiment was designed so that the material experiences the same amount of strain at each pass during rolling. The rolling experiment was performed at moderately high temperatures (450, 550 and 650 °C). The microstructures and mechanical properties of the low carbon steel acquired from the two types of rolling experiments were compared. The results revealed that differences of loading path attributed by monotonic loading (plate rolling) and cross loading (bar rolling) significantly influenced the microstructures and mechanical properties such as yield stress, ultimate tensile stress, strain hardening exponent and elongation of the low carbon steel.