Effect of temperature on deformation and fracture behaviour of high strength rail steel

•Temperature-dependence of KIc on entire cross section of high strength rail steel.•True stress–strain curve of rail steel under uniform and non-uniform deformation.•Experimental and numerical study of temperature effect on Vickers indentation tests.

Fracture toughness (KIc), Vickers hardness, and constitutive equation under tensile loading for high strength rail steel were determined at −40, −10 and 23 °C. KIc and hardness were directly determined from experimental testing, while the constitutive equation also relying on finite element (FE) modelling because of the non-uniform deformation during the necking process. The constitutive equation was verified by enabling the FE model of tensile specimen to regenerate the experimentally measured load–elongation curve and cross-section reduction, and applied to the FE model of Vickers indentation to mimic the load–depth relationship. This paper also discusses relevance of the results with those reported in literature.