Microstructural design for damage tolerance in high strength steels

• Published in: Materials letters Vol. 269; p. 127664
• Main Authors: Samei, Javad, Pelligra, Concetta, Amirmaleki, M., Wilkinson, David S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.06.2020; Elsevier BV
• Subjects: Computed tomography; Damage tolerance; Deformation and fracture; Grain refinement; High strength steels; Martensite; Materials science; Retained austenite; Tensile tests; Third-generation steels; Transformation induced plasticity; X-ray techniques; Deformation and fracture; X-ray techniques; Grain refinement; Transformation induced plasticity; Third-generation steels
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.127664

[Display omitted] •Evolutions of damage in 1G and 3G steels are quantified using X-ray tomography.•Grain refinement is found to increase damage tolerance in the steels.•Transformation induced plasticity significantly increases damage tolerance.•Influences of Grain refinement and TRIP are reported on RT model coefficients.•Grain refinement and TRIP are recommended for microstructural design of 3G steels. We have investigated the capabilities of first and third-generation high strength steels for sustainable accommodation of microstructural damage before fracture occurs. Steels have been subjected to tensile tests followed by X-ray computed tomography to record the evolution of microstructural damage during deformation. Damage growth is correlated with the Rice-Tracey model. Results show that both grain refinement and transformation induced plasticity of retained austenite to martensite lead to enhanced damage tolerance, leading to the suppression of fracture and improved ductility.