Moltasov A. Development of methods for the calculation of power parameters of butt welding of ring products

The thesis is dedicated to the development of analytical and engineering methods for calculating the forces generated by shunt part bending during the initial gap elimination, landing melted metal and further upsetting during butt welding (BW) of ring products, taking into account the heating of the product periphery by shunt currents. Analytical methods for calculating of the force which expend to bending of the shunt circuit during flash-butt welding (FBW) melting of rings with rectangular cross section, and the rupture force due to elastic deformations accumulated in the shunt part during BW was developed. Engineering methods that allow to determine the bending and rupture forces at BW ring products with arbitrary cross-section and other products of the closed form which is different from the ring was substantiated. The effect of heating the periphery of the product by shunt currents on power parameters of BW was explored. The method of describing of the temperature field in the shunt part was offered and the method for calculating the force due to the action of this field was developed. The problems of stress concentration in the butt welds made by FBW were reviewed. The engineering method of description of the stress state in the areas of stress concentration was improved and extended to the specified type of welded joints. Keywords: flash-butt welding, ring product, shunt circuit, upsetting force, bending force, rupture force, thermal force, stress concentration.