Methodology for testing pipeline steels for resistance to grooving corrosion

The methodology for testing pipeline steels is suggested on the assumption that destruction of pipes in field oil pipelines by mechanism grooving corrosion simultaneous fulfillment such conditions as occurrence scratches lower generatrix pipe, eventually growing into a channel form groove, emulsion enrichment with oxygen, presence pipe wall metal stressed state, chlorine-ion oil-water required. Tests are to be carried out 3 % aqueous solution NaCl continuous aeration air bent plates 150×15×3 mm, made analyzed steel, middle part which under action residual stresses ?res, close level maximum equivalent ?eqv pipeline, cut this inner side plate an initiator additional mechanical stresses. Using value modulus normal elasticity degree strain elastic-plastic body from material, corresponding ?res ? calculated, based required deflection angle, after applied them. After keeping corrosive medium each them increase depth result walls analyzed, rate steel K calculated taking account duration tests. Corrosion values two grades determined procedure given. comparison obtained leads conclusion about higher resistance 09G2S steel.