Page 83 - Failure Analysis Case Studies II
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Fig. 7. One of the clusters of cracks In the HAZ on the reducer side of the weld joining the X-side reducer to
the 8 in. pipe HAZ The whole cluster IS about 3 8 mm top to bottom.
Fig. 8. This is close to one of the clusters of cracks in the reducer’s HAZ. There are isolated grain boundary
cavities, i, aligned groups of cavities, ac, and microcracks produced by the coalescence of aligned groups, mc.
These are three stages in the progressive generation of creep cracks. (As in Figs 5-7, this is a coarse-grained
region of the HAZ.) (Nital etch, bright field.)
