Evaluation of mechanical properties is a powerful tool for investigating an
d assessing the performance of service exposed materials. The trends recent
ly observed in service exposed (32 years) plain carbon steels used as a rea
ctor vessel material in a petrochemical plant have been highlighted in this
paper. Health assessment of both base and welded joint was made using impa
ct tests at room temperature, destructive accelerated stress rupture and te
nsile tests at different temperatures, and some nondestructive tests. From
the stress rupture tests it could be concluded that a life of more than 10
years at the hoop stress level of the material can be obtained, provided no
localised damage in the form of cracks or dents have been developed. It is
recommended that a health check should be carried out after 5 years of ser
vice exposure at 485 degrees C. (C) 2000 Elsevier Science Ltd. All rights r
eserved.