Abstract
Ferrite of austeno-ferritic stainless steels maintained for a long time at temperatures in the range of 270 °C to 400 °C is embrittled like the known 475 °C embrittlement of ferritic stainless steels. Deformation and damage micromechanisms of a material must be known in order to apply the local approach to fracture (LAF) methodology. In this work we test a previous model of damage nucleation and evolution, extending its validity to low temperature - long term aging. We have determined cracking damage evolution by taking replicas of planar tensile specimens during uniaxial traction tests. Voronoi (Dirichlet) tessellation quantitative metallography was applied to characterize and quantify non-uniform damaging. Clustering criteria allowed the determination of the size, density and internal damaging rate of damage clusters.
Highlights
Corrosion resistant stainless steels (ASTM CF3, CF8 and CF8M) are widely used in cast components of the primary circuit of nuclear power plants
Joly[3] includes the nucleation term, when he applies this model to the case of aged duplex stainless steels
Following Joly’s idea, we asume that the crack nucleation rate is a random value, corresponding to an uniform value in a segment and null outside
Summary
Corrosion resistant stainless steels (ASTM CF3, CF8 and CF8M) are widely used in cast components of the primary circuit of nuclear power plants. Cavities nucleate exclusively at the onset of plastic deformation and only its subsequent growth produce the critical condition for the fracture. This is why in many Gurson model implementations the nucleation term is not included. Joly[3] includes the nucleation term, when he applies this model to the case of aged duplex stainless steels He found that the number of cracks is proportional to the plastic deformation. Following Joly’s idea, we asume that the crack nucleation rate is a random value, corresponding to an uniform value in a segment and null outside This model was developed studying the damage and fracture mechanisms of accelerated aged duplex steels. The parameters obtained will be used to calculate the fracture toughness of one of the aged conditions in the second part of this work[6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
