Influence of a stop in the process of melting on mechanical properties of specimens from the Co‒Cr‒Mo alloy made by SLM technology

Abstract

The known methods of welding railway rails in terms of their efficiency, productivity and ability to provide the quality of welded rails in accordance with the requirements of standards in force were analyzed. When evaluating the efficiency of different methods of welding, the technological features of formation of welded joints, values of mechanical properties, macro-and microstructure of the joints, the probability of defects formation, efficiency and possibility of automation of the welding process were taken into account. It is shown that such welding methods as thermit, automatic electric arc, gas-pressure and electric resistance found practical application. The varieties of the latter are flash-butt welding (FBW) using continuous flashing, FBW with resistance preheating and FBW with pulsed flashing. FBW technology with pulsed flashing allows providing optimal thermal cycles when welding steels with different chemical composition and properties and ensures compliance of welded joints with the requirements of standards in force. Scientific, technological and design developments of E.O. Paton Electric Welding Institute (PWI) were implemented in a series of stationary and mobile rail welding machines, which are equipped with mobile rail welding complexes, successfully introduced in many countries of the world.