| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1469797 | Corrosion Science | 2011 | 9 Pages |
Stress corrosion cracking (SCC) in the fusion boundary (FB) region of an Alloy 182-low alloy steel (LAS) dissimilar weld joint in 288 °C water was investigated by experiments and finite element simulation. Creviced bent beam and crack growth rate (CGR) experiments showed that, while the FB was a barrier to SCC growth, further crack growth into LAS was activated by a combined effect of sulfate and dissolved oxygen in water. Finite element simulation suggested that a positive gradient of hardness as the crack approached to the FB in dilution zone caused decreased CGR. Role of microstructure and water chemistry in SCC was discussed.
► Hardness gradient in the high hardness zone adjacent to fusion boundary in dilution zone. ► Combined effect of dissolved oxygen and sulfate concentration on crack growth in fusion boundary region. ► 400-ppb Sulfate in water for reactivating crack growth at fusion boundary at K = 30 MPa√m under normal water chemistry. ► Decreased crack growth rate in the high hardness zone is expected due to the hardness gradient. ► Reactivation of crack growth from the pitting at fusion boundary by preferential oxidation along the grain boundary.
