A Two-Stage Crack Growth Model Incorporating Environmental Effects

A new two-stage crack growth model has recently been proposed by Dong et al (2003) to provide a unified description from an infinitesimally small crack exhibiting anomalous crack growth behavior to long cracks that are typically characterized by Paris law. As a result, both short crack anomalous crack at notches and long crack growth data can be unified into a single curve, which provides a fracture mechanics basis for the successful development of the single master S-N curve for weldments (Dong et al, 2001). In this paper, the applicability of the two-stage crack growth model in incorporating environmental effects will be investigated by considering some of the recent available crack growth rate data on 304 SS subjected to an elevated temperature aqueous environment by Wire and Mills (2002). The applicability of the master S-N curve method for weldments for incorporating environmental effects will be discussed in light of the findings from this investigation.