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THE INFLUENCE OF AGEING AT INTERMEDIATE TEMPERATURES ON THE MONOTONIC STRESS‐STRAIN BEHAVIOUR AND FRACTURE TOUGHNESS OF A DUPLEX STAINLESS STEEL
Author(s) -
Iturgoyen L.,
Anglada M.
Publication year - 1997
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1997.tb00298.x
Subject(s) - materials science , fracture toughness , toughness , ductility (earth science) , strain hardening exponent , metallurgy , duplex (building) , ultimate tensile strength , ageing , composite material , hardening (computing) , austenite , dynamic strain aging , microstructure , creep , dna , layer (electronics) , biology , genetics
— The mechanical behaviour of the duplex stainless steel AISI 329 has been investigated for ageing times up to 15,000 h at 475, 425, 375, 325 and 275°C. The study has concentrated on changes in the monotonic stress‐strain behaviour and fracture toughness as a function of ageing temperature and time. It is shown that the tensile behaviour of the steel changes strongly due to ageing. A large increase in yield strength and reductions in ductility and fracture toughness are observed. The deformation hardening behaviour of the aged steel is explained by using a model based on a modified rule of mixtures. Finally it is shown that the higher toughness of aged duplex stainless steels, in comparison with ferritic stainless steels aged under the same ageing conditions, may be associated with the increase in crack growth resistance induced by ductile ligaments of austenite which bridge the crack faces.