PROPERTIES OF JOINTS WELDED USING THE MAG METHOD S355J2+N STEEL AFTER PEENING PROCESS

The aim of the research was to determine the impact of peening of each weld on the properties of a butt joint made of S355J2+N steel welded using a ceramic washer. The welding process was carried out using the MAG method on a robotic station. The analysis was based on a comparison of three butt joints: after welded, with peening of each bead and with post weld heat treatment – stress relief annealing. High frequency peening (90Hz) of each bead made was intended to reduce stress in the weld joint by introducing compressive stress into it. A Weld Line 10 pneumatic hammer was used. Tests such as visual, penetration, radiographic and destructive tests (macroscopic, transverse tensile test, transverse bending test, impact strength test, hardness) are conducted on the test samples prepared in the MAG process. The test results are compared to the acceptance values from the ISO standard. Additionally, stress measurements were made using the Barkhausen effect based on the research procedure of the technology supplier. The research performed showed that use of high – frequency peening after each bead did not affect the negative results of all the required tests during the qualification of the welding technology of S355J2+N steel compared to the test plates (after welded and after post weld heat treatment – stress relief annealing).