STRUCTURE AND PROPERTIES OF WELDED JOINTS OF VANADIUM MICRO-ALLOYED REINFORCEMENT
The causes of embrittlement of welded joints of reinforcing steels micro-alloyed with vanadium were investigated. It is found that welding at negative temperatures causes an increase in the cooling rate of the metal, which leads to the formation of hardening structures in the welded joint. The use of preheating steels of class A500C causes a decrease in the tensile strength of the base metal. A drop in the impact viscosity of slowly cooled samples was also noted. The technology of mechanized welding in a reducing atmosphere based on carbon monoxide was proposed, which provides additional heating of the metal with a gas flame, as well as satisfactory protection of the weld pool. Due to the continuous superposition of a multi-pass weld, an equilibrium ferrite-pearlite structure with satisfactory hardness is formed. The strength of the welded joint meets the requirements of normative documents.