Theinternalstressinducedbyaporouslayerorpassivelayercanassisttheappliedstresstopromotedislocationemissionandcrackpropagation,e.g.whenthepipelinesteelisburiedinthesoilcontainingwater,resultinginstresscorrosioncracking(SCC).Moleculardynamics(MD)simulationisperformedtostudytheprocessofdislocationemissionandcrackpropagationinaslabofFecrystalwithandwithoutaporouslayeronthesurfaceofthecrack.Theresultsshowthatwhenthereisaporouslayeronthesurfaceofthecrack,thetensilestressinducedbytheporouslayercansuperimposeontheexternalappliedstressandthenassisttheappliedstresstoinitiatecracktipdislocationemissionunderloweredstressintensityKI,orstress.Torespondtothecorrosionaccelerateddislocationemissionandmotion,thecrackbeginstopropagateunderloweredstressintensityKI,resultinginSCC.
