Creep Life Assessment of a Super-Heater Tube

Characteristics of creep deformation for ۲.۲۵Cr -۱Mo  were studied using the Monkman–Grant relation. A series of creep tests were conducted on ۲.۲۵Cr -۱Mo   at low-stress levels and at different temperatures ranging from ۶۵۵ ۰C to ۶۸۵۰C . The analysis of creep data indicates that ۲.۲۵Cr -۱Mo is practically supported by Monkman-Grant relationship. Yet, this paper highlights the foremost difficulties associated with the parametric fitting techniques. The damage tolerance factor has been estimated to demonstrate its reliance on the loading conditions and to categorize the material strain concentration. It has been shown that at ۵۵MPa and T=۶۸۵۰C , the tertiary creep stage is not well characterized. Also, this paper identifies a need to provide a serious consideration for an appropriate creep strength factor that would be applied to pressure vessels and to improve the criteria related to design against creep and the prevention of failure.

Keywords:

Creep life assessment , Remnant life , Monkman-Grant , Creep deformation mechanism , ۲.۲۵Cr -۱Mo