This CWA describes a single-specimen testing procedure for the evaluation of a cracking resistance index (CRI) for AHSS sheets with thicknesses between 0,5 mm and 3,0 mm.
NOTE 1 The test method provides an estimated measure of the fracture resistance of thin AHSS in the presence of a crack.
NOTE 2 The proposed CRI must be used only as a fracture toughness index for material screening.
NOTE 3 The suitability of the test to estimate the cracking sensitivity of AHSS has been evidenced in a previous work by establishing a good correlation between the CRI, the EWF and the Hole Expansion Ratio (HER) for a wide range of multiphase AHSS grades .
NOTE 4 It must be emphasized that the results of the test are greatly affected by the specimen thickness. Therefore, it is recommended the use of specimens with similar thicknesses for comparative purposes.