Stability of intemetallic phases in the heat affected zone depending on shielding gases

Abstract

This contribution deals with the influence of shielding gases on the parameters of MIG and MAG welds. For the experiment purposes, steels S 235 JRG1 and C45 were chosen. In the research part, welding parameters and welding conditions were proposed; based on them, a series of experiments were performed. Weld beads were subjected to metallographic analysis (samples prepared according to ČSN ISO 4967), from which the heat-affected zone and metal structure were determined. The melting bath area was not analyzed. Furthermore, in the heat-affected zone there were hardness and microhardness measured. The macrohardness of the samples was measured using the Rockwell HRB method according to ČSN EN ISO 6508 standard. The microhardness measurement was performed using Hannemann microhardness tester according to ČSN EN ISO 6507-1 standard.