Adiabatic shear localization of different steels at high strain rates

Abstract
The adiabatic shearing behavior of S15C low carbon steel, S50C medium carbon steel, and SKS 93 tool steel with a high carbon and low alloy content (abbreviated to high carbon steel hereafter) is examined using a compressive-type split-Hopkinson pressure bar (SHPB) at strain rates ranging from (5 ~ 20) × 10⁴ s⁻¹ to 2,0 × 10⁵ s⁻¹. Metallographic observations of the sheared specimens suggest that the shear flow stress and the hardness and width of the shear band depend strongly on the carbon content and strain rate. The formation of the deformed and martensitic transformed shear bands is a function of the carbon content and the shear load. The fracture surface of the low carbon steel exhibits a dimple-like structure. However, the fracture surfaces of the medium and high carbon steels exhibit both a dimple-like structure and knobby features. The formation of the knobby features is attributed to an increased carbon content and a higher strain rate.