Interaction between microalloying additions and phase transformation during intercritical deformation in low carbon steels

Heavy gauge line pipe and structural steel plate materials are often rolled in the two-phase region for strength reasons. However, strength and toughness show opposite trends, and the exact effect of each rolling process parameter remains unclear. Even though intercritical rolling has been widely st...

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Detalles Bibliográficos
Autores: Mayo-Ijurra, U. (Unai)|||/items/5e7d9761-2183-4d7c-a4a5-4398bbf75a47, Isasti-Gordobil, N. (Nerea)|||/items/1db68ad7-6dff-4e04-a6f0-760c21a58a57, Rodriguez-Ibabe, J.M. (José María)|||/items/c2dfc7a7-5e52-4aeb-bfbc-7ec0c1c0452a, Uranga-Zuaznabar, P. (Pello)|||/items/2b9b950d-94af-4494-aeb9-daf83d5d4e1f
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad de Navarra
Repositorio:Dadun. Depósito Académico Digital de la Universidad de Navarra
Idioma:inglés
OAI Identifier:oai:dadun.unav.edu:10171/62731
Acceso en línea:https://hdl.handle.net/10171/62731
Access Level:acceso abierto
Palabra clave:Intercritical rolling
Microalloying
Microstructure
EBSD
Descripción
Sumario:Heavy gauge line pipe and structural steel plate materials are often rolled in the two-phase region for strength reasons. However, strength and toughness show opposite trends, and the exact effect of each rolling process parameter remains unclear. Even though intercritical rolling has been widely studied, the specific mechanisms that act when different microalloying elements are added remain unclear. To investigate this further, laboratory thermomechanical simulations reproducing intercritical rolling conditions were performed in plain low carbon and NbV-microalloyed steels. Based on a previously developed procedure using electron backscattered diffraction (EBSD), the discretization between intercritically deformed ferrite and new ferrite grains formed after deformation was extended to microalloyed steels. The austenite conditioning before intercritical deformation in the Nb-bearing steel affects the balance of final precipitates by modifying the size distributions and origin of the Nb (C, N). This fact could modify the substructure in the intercritically deformed grains. A simple transformation model is proposed to predict average grain sizes under intercritical deformation conditions.