材料期刊网

A gas turbine was initially damaged due to the impinging of broken pieces of the first-stage shroud segments against the second-stage buckets. The shroud segments were embrittled by precipitation of sigma-phase at high temperature and cracked under thermal stress. The formation of sigma-phase in the cracked shroud segments was promoted by the elements Si and Cr in greater amounts than in a normal shroud segment. The cracking of the shroud segment was identified by simulation tests in a laboratory.