Quasistatic fracture behaviour and defect assessment of brazed soft martensitic stainless steel joints

Brazed components are widely applied in industry and are often subjected to complex loading conditions. Even if such components often contain brazing defects, no failure assessment procedures for brazed joints are reported in the literature. In this work, the deformation and the quasistatic behaviour of brazed joints of the martensitic stainless steel X3CrNiMo13-4 were investigated. This includes the determination of stress–strain-curves as well as of the fracture toughness. In addition, the mechanical behaviour of components such as specimens with T-joint geometry under tensile loading were characterized. In order to consider the effect of brazing defects on the structural integrity, typical defects with different sizes and geometries were introduced in the brazing zone. The experimentally determined material parameters were used for additional numerical deformation analyses by means of finite elements (FE). Both the experimental and the numerical results were in good agreement with predictions according to the R6 method and provided a basis for the engineering defect assessment of brazed components based on failure assessment diagrams.