A more appropriate FE model to predict the creep crack initiation and growth behavior of brazed joint

In this paper, a more appropriate finite element (FE) model was proposed to predict the creep crack initiation (CCI) and growth (CCG) behavior of HastelloyC276-BNi2 brazed joint at high temperature. The effects of single-material, bi-material and three-material method on CCI and CCG behavior have been discussed fully. The relationships between CCG rate and parameter C∗ for different simulation methods were obtained. The results show that the simulation method has a great influence on CCI and CCG behavior of brazed joint. The brazed residual stress (RS) can accelerate CCI and enhance CCG rate, leading to the reduction of creep life. The CCI time and creep life predicted by single-material method is smaller than those by bi-material and three-material method. The creep life and crack growth morphology predicted by single-material method have a good consistent with the experimental results. The single-material method can accurately predict the CCG behavior of brazed joints. Bigger uniaxial creep strain can prolong the CCI time and reduce the CCG rate. The creep life of brazed joint can be enhanced by increasing uniaxial creep strain.