Perspectives of creep and fatigue behavior in microalloyed steels

Abstract

This is study of microalloyed steels for power plants and reactors. Components operate at coal dust fire temperature or thermal states of reactors are prone to creep during its service. This is to assess remaining life after passage of valuable life by variation in microstructure, e.g. cavity formation. Precipitation at the sub-grain boundaries and grain interior has increased high temperature strength. Coarsening of these appears at the end of life. Variation of heat treatment like spheroidising in place of solutionizing has been responsive to deteriorate performance. Dislocation interplay with precipitate has showed to be acceptable while interaction among dislocations to forest dislocation has been unacceptable. Dislocation assisted nucleation of precipitates of fine size has found to strengthen steel by thermo-mechanical control process with in greater heating temperature and lower finish rolling temperature. High temperature performance of materials have assessed by creep, accelerated creep, creep-fatigue and fatigue performances. Increasing temperature for increasing efficiency has correlated the phase transformation of steel. Fracture studies have referred any consequences those produce grain boundary phase formation has likely been to fracture by intergranular failure. Fatigue performances have included in creep properties of materials when intermittent shut down -shut up schedules are operated, e.g. peaking power plants.