Investigation of the structure and properties of welded joints obtained by contact-arc welding from rail hoist grade E76HF

Abstract

The structure of the welded joint of E76KhF rail steel was studied under various modes of contactheating. Optical microscopy methods have been used to study and describe the structure in variousparts of the metal in the heat-affected zone. It has been established that the welded joint of the studiedsamples has several zones with different structures, among which it is possible to distinguish: a zonethat is a finely dispersed lamellar perlite (sorbite) with areas of troostite; a zone of coagulated sorbitol;zone, the microstructure of which is typical for the main rail metal in the heat-strengthened state.It was found that contact heating after flash butt welding reduces the amount of martensite in the weldzone. In the course of the study, the optimal parameters of contact heating were determined, usingwhich it is possible to obtain a material structure that makes it possible to increase the service life ofthe rails.