Determination of the critical parameters for the onset of dynamic recrystallization (DRX) in advanced ultra-high strength steels (A-UHSS) microalloyed with boron

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Determination of the critical parameters for the onset of dynamic recrystallization (DRX) in advanced ultra-high strength steels (A-UHSS) microalloyed with boron

Gerardo Altamirano Guerrero1, Ignacio Mejía Granados1, José María Cabrera Marrero2,3

1Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 – Morelia, Michoacán, México.
2Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB – Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 – Barcelona, Spain.
3Fundació CTM Centre Tecnològic, Av. de las Bases de Manresa, 1, 08240 – Manresa, Spain.

DOI:

https://doi.org/10.7494/cmms.2012.3.0393

Abstract:

In this research work, the double differentiation mathematical method was used to identify more accurately the criti) and critical strain ) associated with the onset of dynamic recrystallization (DRX), which is based on cal stress changes of the strain hardening rate / ) as a function of the flow stress (Poliak and Jonas method, simplified by Najafizadeh and Jonas). For this purpose, a low carbon advanced ultra-high strength steel (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm) was deformed by uniaxial hot-compression tests at high tempe). Results indicate that ratures 950, 1000, 1050 1100° ) and constant true strain rates 10 , 10 10 both and increase with decreasing deformation temperature and increasing strain rate. On the other hand, these critical parameters tend to decrease as boron content increases. Such a behavior is attributed to a solute drag effect by boron atoms on the austenitic grain boundaries and also to a solid solution softening effect.

Cite as:

Guerrero, G., Granados, I., & Marrero, J. (2012). Determination of the critical parameters for the onset of dynamic recrystallization (DRX) in advanced ultra-high strength steels (A-UHSS) microalloyed with boron. Computer Methods in Materials Science, 12(3), 152 – 162. https://doi.org/10.7494/cmms.2012.3.0393

Article (PDF):

Keywords:

Advanced ultra-high strength steels, Hot deformation, Dynamic recrystallization, Critical stress, Critical strain, Strain hardening rate

References: