Effect of special features of distribution of nonmetallic inclusions in the metal of electric-welded oil conducting tubes on resistance to hydrogen-stress cracking

Results of an analysis of fracture surfaces obtained by the method of eccentric detachment of specimens of the metal of welded tubes from steel 09GSF in the initial state and after testing for hydrogen-stress cracking in a hydrogen sulfide medium are presented. Qualitative dependences of the susceptibility of the steel to hydrogen-stress cracking and of the kind of fracture in the initial stage and after testing for hydrogen-stress cracking on the purity of the metal with respect to nonmetallic inclusions in the zone of axial segregation are established. The dependences are used for developing a method for diagnosing rolled stock.