EFFECT OF THERMAL CYCLE OF TIG WELDING ON STRUCTURE AND PROPERTIES OF PSEUDO-β-TITANIUM ALLOYS

摘要

The structural pseudo-β-titanium alloys have found a wide application in aircraft and rocket construction. However, while producing welded joints of pseudo-β-alloys applying method of fusion welding, the difficulties arise connected with change in the structure and formation of metastable phases in welded joint. In this paper, using the developed mathematical model of TIG process, the influence of welding thermal cycle on the weld shape, cooling rate and structure of welded joint metal of the pseudo-β-titanium alloy VT19 was investigated. Amount of phases in the weld metal, heat-affected zone and base metal was determined, phase composition and its effect on the mechanical properties of welded joints were predicted.