Activities to advance residual life evaluation techniques for highly aged power boiler materials

ABSTRACT

In Japan, national guidelines of residual life evaluation for aged thermal power equipment were formulated in 1999. Several issues had recently come to light with the increase in ageing systems, including the emergence of unexpected mode of creep damage, the verification of practical applicability of the damage calibration curve generated in the laboratory, how to deal with creep-fatigue damage due to increased numbers of plant starts and stops, occurrence of plastic deformation in the accelerated creep test and the need for the creep damage monitoring method during plant operation. The Working Group to Advance Residual Life Evaluation Techniques was established in 2011 within the Society of Materials Science, Japan, to identify issues and discuss improvement measures. This paper provides an overview of the results of the working group activities.

KEYWORDS:

• Thermal power boiler
• high energy piping
• residual life evaluation
• 2.25Cr-1Mo steel
• thermal expansion stress
• creep damage
• type IV failure
• fine-grained HAZ
• damage monitoring

Disclosure statement

No potential conflict of interest was reported by the author(s).