Influences by Inclusions on Hydrogen Sulfide Corrosion-resistances of Tubing/Casing and Linepipe

Studied in the article are the influences by the inclusions on the hydrogen sulfide corrosion-resistances of tubing/casing and line-pipe. The result reveals that the large-sized Type B inclusion as cracking source would lead to the early fracture of the specimen under the Method A SSC test，and flakes as formed by both surface and internal inclusions would introduce cracking. Inclusions would also lead to flakes on fracture surface of the specimen under the Method D double-cantilever-beam（DCB） test，and in turn lower the critical stress intensity factor K_ISSC. Likely，flakes would be found on the fracture surface of the specimen as non-stress hydrogen permeated under tensile test.Inclusions of Types A，B and D could all develop hydrogen blisters under hydrogen-induced cracking（HIC） test，and size of the hydrogen blister is related to that of the inclusion，and aggregation level thereof.