Numerical and Experimental Investigations on the Defect Tolerance of Brazed Steel Joints

Abstract

Abstract Based on the combination of FE-calculations and experimental results a defect assessment procedure for brazed steel joints was developed in the present work, which reliably takes into account the effect of different steel heat treatments and defined artificial defects in the braze layer. Tensile tests with defect free joints consisting of X3CrNiMo13-4 as substrate material and of Au-18wt.-%Ni as filler metal serve as a basis to simulate the elastic-plastic material behaviour. By correlating experimental and numerical methods, failure criteria could be derived which indicate and predict failure of brazed components. These failure criteria were also presumed to calculate the maximum tolerable loads for specimens containing different defects. The results show that the simulations correlate very well with the experimental results. Furthermore, they provide a possibility to analyze the failure behaviour for different defect types and the influence of different heat treatments on the joint strength.