Abstract
The paper is devoted to an analysis of mechanical and metallurgical consequences of a stress-test applied to a welded joint of a pipeline manufactured from spirally welded pipes of thermomechanically rolled steel grade StE 480.7 TM. The pipeline was welded as a whole using basic vertical down electrodes without application of preheating and additional heat treatment. During the stress-testing, an irreversible integral deformation of 1 promile was attained on the circumference of the pipes. The result of the testing was a change in distribution of the localized internal stresses and an increase of working safety and reliability of the pipeline system. After making this test, neither microcracks nor other types of defects were detected in welded joints of the StE 480.7 TM steel grade.

Key words
mechanical characteristics, stress-test, steels

Full text not available