The Influence of Corrosion Dissolution of the Metal Surface Layer on the Stress Concentration Factor in Butt-Welded Joins

The dissolution of the metal surface layer of butt-welded joints samples made of 09G2S steel by the anodic-cathodic process in the electrolyte, as a result of which the geometric parameters of the welded joint changed, was studied. For example, after corrosion tests the radius of transition from the weld metal to the base metal on the facial side of the joint increased from 3.07 to 3.88 mm, and on its root, side increased from 2.16 to 3.09 mm. Changes in the geometrical parameters of a welded joint affect the value of the stress concentration factors (SCF), which determine fatigue life of the welded joints Therefore, analytical calculations of the SCF in the sample of the 09G2S steel butt-weld before and after dissolution of the metal surface layer were performed. In this case, the existing formula for SCF determination on the root side of the joint was modified for the case when the bases of facial and root reinforcements were close enough. It was found that after corrosion dissolution of the metal surface layer, the maximum value of the SCF in the specimen decreased from 1.87 to 1.67.