Effect of aging on elevated temperature ductile fracture toughness of type 316LN stainless steel/alloy 800 weldment

摘要

A type 316LN stainless steel/alloy 800 dissimilar metal weld, welded using Fe–16Cr–8Ni–2Mo (wt-%) filler metal, was subjected to accelerated aging heat treatments at 873 K for up to 5000 h to simulate long term service exposures, and was characterised for elevated temperature service at 773 K. The analysis included, apart from conventional structure–property correlation, characterisation in terms of the empirical parameters _f and _f determined at 773 K. The parameters _f and _f characterise the resistance to ductile fracture and are determined from tensile tests of smooth cylindrical transverse weld specimens. The results show that the present weldment has adequate stability against elevated temperature aging, and should therefore show stable behaviour on exposure at the service temperature.