Fracture Toughness Calculation Method Amendment of the Dissimilar Steel Welded Joint Based on 3D XFEM

Abstract

The dissimilar steel welded joint is divided into three pieces, parent material–weldmetal–parent material, by the integrity identification of BS7910-2013. In reality, the undermatchedwelded joint geometry is dierent: parent material–heat aected zone (HAZ)–fusion line–weld metal.A combination of the CF62 (parent material) and E316L (welding rod) was the example undermatchedwelded joint, whose geometry was divided into four pieces to investigate the fracture toughness of thejoint by experiments and the extended finite element method (XFEM) calculation. The experimentalresults were used to change the fracture toughness of the undermatched welded joint, and the XFEMresults were used to amend the fracture toughness calculation method with a new definition of thecrack length. The research results show that the amendment of the undermatched welded jointgeometry expresses more accuracy of the fracture toughness of the joint. The XFEM models wereverified as valid by the experiment. The amendment of the fracture toughness calculation methodexpresses a better fit by the new definition of the crack length, in accordance with the crack routesimulated by the XFEM. The results after the amendment coincide with the reality in engineering.