Microstructural design for damage tolerance in high strength 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.