THE INFLUENCE OF THE COMPOSITION OF THE FLUX ON THE METAL STRUCTURE OF THE SEAMS MADE WITH A MODIFYING GRANULATED ADDITIVE
The article is devoted to the problems of increasing the toughness of welded joints of critical metal building structures. It is shown that in automatic submerged arc welding on a layer of a metal-chemical additive (MHP), the modifying effect of titanium dioxide, which is part of MHP, depends on the chemical composition of the flux. The greatest grain refinement in the seam of welded joints made of steel 09G2S was observed in submerged-arc welding AN-47 with a high content of aluminum oxide Al2O3 (9-13%). In submerged arc welding AN-348A containing no more than 6% Al2O3, the structures of welds made with a granular filler (wire chips Ø 2.0 × 1.5 mm Sv-08G2S) without TiO2 and with 0.4% TiO2 do not differ apart. This indirectly indicates that the resulting complex refractory TiAl2O5 compounds are endogenous centers of crystallization of the weld pool, on the basis of which a fine-grained weld structure is formed.