Roentgenometrical detection of weakening pipe steel signs

The aim of this investigation is to determine the roentgen and diagnostic signs of the destruction in steel pipes by revealing the dependence of the internal stresses distribution in metal on the repeated loading with cooling deformation. Steel pipe 10, 20, 12X1MF were used. Samples cut from the steel were subjected to cool strain cycling in adding planar stressed state by means of press with the fixed value of the external pressure. For every surface, nine cycles were carried out in series with increasing loading. Following every loading cycle, radiography of the internal and external surfaces was performed.