Study of Rotary Friction Welding as an Alternative to Resistance Welding in High-Carbon Steel Wires: Effects on Fatigue and Hydrogen Embrittlement

Abstract High-carbon steel wires (0.7%C) are widely used in engineering due to their high strength and versatility. Among their various applications, their use under severe conditions, including embrittling environments and fatigue loading, is particularly noteworthy. Wire welding can introduce imperfections and weaken the material, an effect further aggravated by hydrogen-inducing agents. Although butt resistance welding is the most commonly employed technique for wires, it presents several limitations. This study investigates rotary friction welding as an alternative process, evaluating fatigue resistance and hydrogen embrittlement in 5.2 mm diameter wires, in comparison with the conventional resistance welding method. The results showed that friction-welded joints exhibited an approximately 90% increase in fatigue life and effectively eliminated the hydrogen embrittlement susceptibility observed in resistance welds, raising the success rate in testing from 20 to 100%. It is concluded that the rotary friction process reduces the formation of brittle microstructures and provides high resistance to hydrogen embrittlement. Therefore, the adoption of rotary friction welding is recommended for critical applications of high-carbon steel wires subjected to fatigue and hydrogen-susceptible environments.