Fracture toughness characterization of advanced high strength steels by means of the essential work of fracture

Fracture toughness cannot be readily measured in metal sheet because the small thickness in which they are used (1-3 mm). In this sense the essential work of fracture (EWF) has been successfully applied to determine fracture toughness in polymers films and many metal sheets. However, their information about the applicability of this methodology to AHSS is relatively scarce. In the present work the fracture toughness of some advanced high strength steel Dual Phase and drawing steel sheets has been measured by means of the EWF. The results show that AHSS steels with yield strength up to 800 MPa meet the requirements of the method, and therefore the values obtained for the EWF are valid. Thus, the EWF is postulated as methodology to evaluate the fracture toughness and can be used as a mechanical parameter to characterize the fracture behavior during crash of AHSS steel sheets