Characterization of the Type Ⅳ crack in high Cr steel weldments

摘要:

Abstract:

The weldments for several types of high Cr ferritic steels were investigated to understand the fracture mechanism of the Type Ⅳ crack. The creep testing shows that the Type Ⅳ cracking is more likely to occur at the lower stress level, whereas at the higher stress level the crack shifts towards parent metal. The microstructures observed in the HAZ for all the materials are mostly tempered lath martensites. There was no δ ferrites found in all creep specimens.