Psareva I. The perfection of welding on metal of metallurgical equipment technology by joints of regulated form.

The dissertation is about research of working surface formation process by arc welding by joints of regulated form, technology and equipment development to raise service characteristics of strengthened parts, lowering of physical and power resources expenditure while producing and exploitation. It is determined that to provide a high - quality layer surfaced by arc welding, it is necessary to form it by beads of regulated form: curved with plain and discreet changing of surfacing trajectory; by combination of continuous surfaced layer and layer formed of discreet sections. It is determined that at the initial stage of the formation of puddle the heat transfer in it is implemented mainly by heat conductivity, and then when flows appear in it - the transfer of heat from source to welding limit by molten metal flows. At the same time at the beginning of puddle formation its temperature rises sharply and its volume - slightly. With appearance of flows in it at the second stage the molten metal temperature(averaged by volume) falls sharply and the volume of puddle metal increases Upon this the method of continuous surfacing of working surface as discreet sections It is determined that the main role of heat transfer by molten metal flows lead to independence of width and depth of puddle from plate thickness in wide range of plates thickness on which bead is surfaced. And reflected from its backside heat stream influences just the form of rear part of puddle. It is also shown that the limit of melting and hardening fronts division in the puddle may be convex when metal along axis of joint hardens earlier then periphery sections at the edges of the puddle. As well as it may be concave when this processes interchange. It is determined that the form of limit division depends of intensity of axis deep and surface flows of puddle metal correlation and influences the quality characteristics of weld bead. The technological processes and automated equipment for working surface facing by beads of regulated form which wastested at Mariupol Illich iron and steel works and Dnepropetrovsk metallurgical equipment plant have been developed these tests showed high service characteristics at equipment, its reliability in operation, the simplicity of technological processes at hardening.