The effect of the location of stage-I fatigue crack across the persistent slip band on its growth rate – A 3D dislocation dynamics study. Issue 16 (3rd June 2017)

• Record Type: Journal Article
• Authors: Prasad Reddy, G. V.; Sandhya, R.; Laha, K.; Depres, C.; Robertson, C.; Bhaduri, A. K.
• Is Part Of: Philosophical magazine. Volume 97:Issue 16(2017)
• Page Start: 1265
• Page End: 1280
• Publication Date: 2017-06-03
• Subjects: Dislocation dynamics -- stage-I fatigue crack -- persistent slip band -- crack tip slip displacement -- cyclic plasticity; Condensed matter -- Periodicals; Physics -- Periodicals; Matière condensée -- Périodiques; Physique -- Périodiques; 530.41
• DOI: 10.1080/14786435.2017.1294269
• Languages: English
• ISSNs: 1478-6435

Abstract

Abstract: A 3D dislocation dynamics study to ascertain the probable path of stage-I fatigue crack propagation across the persistent slip band (PSB) in austenitic stainless steel is presented. Cyclic plasticity and the resulting crack tip slip displacement (CTSD) are evaluated for cracks of varying length introduced at PSB-center and at two PSB-matrix interfaces. CTSD attains high value at either of the two interfaces irrespective of the proximity of crack front to the grain boundary. Further, a difference in microcrack propagation rate is also observed among the two interfaces. The present results assert microcrack propagation preferrentially along one of the two PSB-matrix interfaces rather than at the PSB-center. A pre-existing PSB dislocation structure localises the cyclic slip for crack lengths up to approximately half of the grain depth for an applied strain range of 2 × 10 −4 .