Effect of Material Heterogeneity on Environmentally Assisted Cracking Growth Rate of Alloy 600 for Safe-End Welded Joints

Abstract

Environmentally assisted cracking (EAC) is essential in predicting light water reactors’ structural integrity and service life. Alloy 600 (equivalent to Inconel 600) has excellent corrosion resistance and is often used as a welding material in welded joints, but material properties of the alloy are heterogeneous in the welded zone due to the complex welding process. To investigate the EAC crack growth behavior of Alloy 600 for safe-end welded joints, the method taken in this paper concerns the probability prediction of the EAC crack growth rate. It considers the material heterogeneity, combining the film slip-dissolution/oxidation model, and the elastic-plastic finite element method. The strain rate at the crack tip is a unique factor to describe the mechanical state. Still, it is challenging to accurately predict it because of the complicated and heterogeneous material microstructure. In this study, the effects of material heterogeneity on the EAC crack growth behavior are statistically analyzed. The results show that the material heterogeneity of Alloy 600 can not be ignored because it affects the prediction accuracy of the crack growth rate. The randomness of yield strength has the most influence on the EAC growth rate, while Poisson’s ratio has the smallest.

Yield Load Solutions for SE(B) Fracture Toughness Specimen with I-Shaped Heterogeneous Weld

“…The application of the SINTAP procedure is based on the implementation of the yield load solution in the failure assessment diagram (FAD) to determine the safe operation of the assessed structure. There are a number of studies dealing with various aspects of the fracture behavior of homogeneous welds with strength mismatch compared to the base metal, including recent ones [ 4 , 5 , 6 , 7 , 8 , 9 ], as well as a number of studies dealing with heterogeneity in welds with strength mismatch [ 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”

Special Issue “Extreme Mechanics in Multiscale Analyses of Materials”

“…The papers included in this Special Issue deal with a broad spectrum of interests in analytical, computational, and experimental studies on extreme types of material behaviour. The included papers encompass many areas of extreme mechanics modelling including: a strength investigation using detailed microfractography analysis of fractures formed during static tensile tests of steel Armstal 550 [ 1 ], a study on the effect of NTO content on the properties of an HMX-based cast-PBX (polymer bonded explosive) [ 2 ], the dependency of contact length on cutting speed and other variables performed by the optical method in cutting processes [ 3 ], bone molecular models at the nanoscale [ 4 ], molecular models of bones at the nanoscale, the characterisation of composites’ mechanical behaviour at low temperatures [ 5 ], the diffusion of hydrogen atoms through the grain boundaries of materials, the failure properties of batteries under axial forces [ 6 ], the deformation and failure properties of Ni lithium batteries [ 7 ], the effect of material heterogeneity on the environmentally assisted cracking growth rate of Alloy 600 for safe-end welded joints [ 8 ], the high strain yielding of the additive manufacturing of Inconel 625 through laser melting [ 9 ], the effect of the yield strength distribution of welded joints on the crack propagation path and the crack mechanical tip field [ 10 ], the effect of mechanical heterogeneity on strain and stress fields at crack tips of SCC in dissimilar metal welded joints [ 11 ], and the characterisation of mechanical heterogeneity in dissimilar metal welded joints [ 12 ].…”