Studies on creep behaviour and Statistical analysis of services exposed P-22 grade of Steel

Abstract

The mechanical properties of a component at different locations in a wrought product even from single heat posses some variation because of the presence of localized heterogeneities like segregation of micro-constituents and localized strains in extensively deformed metals and alloys as a result of thermo-mechanical processing or improper heat treatment. A variety of microstructural evolutions can take place in creep exposed materials such as fine precipitation and subsequent coarsening, recovery of excess dislocations, changes in sub-grain size and thickening of sub-grain boundaries due to dislocation dampening, dynamic recovery and recrystallization of matrix structure. The objective of the work is to study the creep behavior of service exposed P-22 grade steel and investigate the scatter characteristics of creep properties such as rupture time, steady state creep rate from repeat data.