Investigation of the quality of joining cylindrical blanks by resistance flash-butt welding

The study aims to evaluate the quality of joints obtained through resistance flash butt welding of cylindrical blanks, with a focus on structural integrity and strength. The research reviewed both domestic and international studies addressing weld improvement and conducted experimental tests on reinforcement bars and steel rods. Welding was performed using the MCP-25 resistance welding machine. Metallographic and tensile tests were applied to assess weld quality. The analysis showed that resistance welding accounts for approximately 40% of all welded joints and is the leading method in terms of mechanization and automation. Butt welding, primarily flash-butt welding, represents 10-15% of this scope. Metallographic tests revealed no cracks, burns, or incomplete fusion in the welds. Tensile tests indicated that welded specimens could withstand loads of 25,000–40,000 N, with fractures occurring near, but not within, the weld zone. Resistance flash butt welding produces joints of sufficient strength and reliability, confirming its effectiveness for joining reinforcement bars and steel rods. The findings demonstrate the applicability of resistance butt welding in various industries, offering reliable and automated solutions for high-strength welded joints.