A new process of arc welding in shielding gases with alternate pulsed supply of dissimilar gases - helium and argon, and also the welding technology based on the process are described. It is shown that as a result of combining the advantages of argon-arc and helium-arc welding in the new process it is possible to increase the strength properties, precision and leak tightness of the welded joints, to ensure absence of defects and to reduce the volume of welding operations. Various physical effects, accompanying the process, are discussed. These processes accompany the process and produce the weld metal with the equiaxed fine-grained structure. © 2013 Copyright Taylor and Francis Group, LLC.