Abstract
Advanced High Strength Steels (AHSSs) are considered one of the key materials for the automotive industry. These steels are characterized by showing very high strength, good global formability and high crash performance, which makes them especially suitable for the development of structural and safety-related automotive components. However, the implementation of these steels has brought new challenges related to their limited damage tolerance and higher cracking susceptibility compared to conventional mild steels. Furthermore, because of their high strength, AHSS may be susceptible to hydrogen embrittlement (HE) when they are exposed to hydrogen-containing environments, increasing thus the risk of catastrophic failure in a crash event. Therefore, evaluating the influence of hydrogen on fracture properties is of primary importance to assess the HE susceptibility of AHSSs and predict potential fractures that can compromise structural integrity during a crash.
In this work, the influence of hydrogen content on the fracture toughness of different AHSS is assessed. Fracture toughness is evaluated by means of the Essential Work of Fracture (EWF) method. The method has shown to be suitable to characterize the crack initiation and propagation resistance of AHSS and it can be used to rationalize their fracture behaviour under impact loading.