Electron beam welding of chromium-molybdenum steel - having high oxygen content with re-melting of each weld projecting weld bead

摘要

Electron beam welding by irradiating basic metal with an electron beam and formation of weld beads, takes place by re-melting the projecting part of each weld bead which forms an expansion of solidifying line of weld bead in direction of welding, after solidification of weld bead surface, while internal part is still in molten condition, by using an electron beam, laser beam or plasma arc jet. Used esp. for welding Cr-Mo steel contg. 1-3 wt% Cr, 0.5-1.5 wt% Mo and 300 ppm O2. Re-melting and re-solidification process allows correction of insufficient filling of central part of bead and prevents formation of pores and cracks. Each bead is pref. re-melted immediately after formation, in course of welding, pref. to 1/3-1/2 of its melting depth.