Investigation of the content of diffusive hydrogen in the deposited metal during welding

he content of diffusible hydrogen in the deposited metal has a significant effect on the mechanical properties of the resulting welded joint, contributing to the formation of cold cracks in the manufactured structures. Therefore, it is important to study the content of diffusible hydrogen when welding with different types of electrodes under different welding conditions to find optimal modes and ways to reduce the content of diffusible hydrogen in the weld metal. The purpose of the work: a comparative analysis of the content of diffusible hydrogen in MR-3 and UONI 13/55 electrodes under different welding modes. Tests were carried out on MR-3 and UONI 13/55 electrodes. The experiments were carried out using 4 mm diameter electrodes with direct and reverse polarity DC. It was found that the content of diffusible hydrogen in MR-3 electrodes is, on average, higher than in UONI 13/55 electrodes both with direct and reverse polarity. However, the highest value of diffusible hydrogen is detected during the experiment with UONI 13/55 electrodes at reverse polarity. Also, based on the data obtained, it can be concluded that the hydrogen content during welding with UONI 13/55 at direct polarity is lower than at reverse polarity, but when welding at direct polarity, welding is unstable and the arc periodically breaks. When welding with MP-3 electrodes, the arc burns stably, both at reverse and direct polarity, but when welding at reverse polarity up to a current value of 140 A, the content of diffusible hydrogen in the deposited sample is on average lower than when welding at direct polarity.