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

J Fail. Anal. and Preven. https://doi.org/10.1007/s11668-026-02455-0 ORIGINAL RESEARCH ARTICLE Study of Rotary Friction Welding as an Alternative to Resistance Welding in High-Carbon Steel Wires: Effects on Fatigue and Hydrogen Embrittlement Antelmo Santos Chaves . Matheus Mariano da Silva Reis . Ihana Gabriela Conceição de Jesus . Renan Celestino Silva Santos . Sandro Griza Submitted: 13 November 2025 / in revised form: 5 May 2026 / Accepted: 7 May 2026  The Author(s) 2026 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 highcarbon steel wires subjected to fatigue and hydrogen-susceptible environments. A. S. Chaves (&)  M. M. da Silva Reis  I. G. C. de Jesus  R. C. S. Santos  S. Griza Federal University of Sergipe (UFS), Post Graduate Program of Materials Science and Engineering, São Cristóvão, SE 49107230, Brazil e-mail: S. Griza Department of Materials Science and Engineering, Federal University of Sergipe (UFS), São Cristóvão, SE 49107-230, Brazil Keywords Steel wires  Welding  Hydrogen embrittlement  Fatigue Introduction High-strength drawn steel wires have a wide range of applications in engineering and industry. They are extensively used in civil structures (bridges, viaducts, walkways, and concrete reinforcements), fastening elements, tying systems, lighting poles, protective grilles, fences, meshes, wire nets, sieves, and drainage systems. They are also widely employed in tension armatures for umbilicals in offshore oil and gas production. In all these cases, exposure to corrosive environments-whether in marine atmospheres, aggressive soils, hydrogen transport, or media containing acidifying gases-can compromise the durability and mechanical integrity of the wires [1, 2]. Wire welding can present significant challenges, particularly in high-carbon steels, where the process may reduce the wire’s strength or increase its susceptibility to fracture. However, these effects can be mitigated through proper control of welding parameters. Furthermore, exposure to corrosive environments, such as in the presence of hydrogen, can accelerate mechanical degradation and compromise the integrity of the weld [3, 4]. The welded region constitutes a critical zone in the joining of metallic components, as the thermal input involved and the heating and cooling rates lead to significant microstructural transformations. These modifications can compromise both the mechanical performance and the corrosion resistance of the wire. Moreover, embrittlement mechanisms, particularly hydrogen embrittlement (HE), 123 J Fail. Anal. and Preven. have gained increasing relevance given the potential future use of pipelines for green hydrogen transport [5–7]. The microstructure of drawn wire must be carefully evaluated for its suitability in hydrogen transport. It is worth noting that high-carbon wires, even prior to welding, exhibit high hardness and strength, which increases their susceptibility to hydrogen embrittlement (HE). This consideration becomes particularly relevant in the context of transporting liquid or gaseous hydrogen [8, 9]. The industry has multiple techniques for wire welding, which can be grouped according to their operational principle: (a) fusion processes, which involve local melting of the material; (b) resistance-based methods, especially butt resistance welding, which utilizes Joule heating; and (c) solid-state techniques, such as friction welding, which promote joining without melting the base metal [10]. Although several welding techniques such as arc welding and laser welding are available, their application to highcarbon steel wires is limited due to high heat input and the associated risk of brittle microstructure formation [11]. In this context, resistance welding remains the industrial standard, while solid-state processes such as rotary friction welding emerge as promising alternatives due to their lower thermal impact and improved microstructural control [12]. The fundamental difference of solid-state welding compared to the other methods is that the temperature reached is relatively low, which offers several advantages, such as reduced formation of volatiles, resulting in a lower environmental impact, greater control of process parameters, and consequently better control over microstructural transformations and final mechanical properties [13]. Rotary friction welding (RFW) and linear friction welding (LFW) are two solid-state welding processes that can be readily applied to wires [14, 15]. RFW is well established, and several published cases are available [16, 17]. Smaller-diameter wires, on the order of 2 mm, can be welded using RFW, which is particularly suitable for highcarbon steel wires that are difficult to join by fusion welding. Welded wires subjected to cyclic loading exhibit a high susceptibility to fatigue failure, particularly in the welded region, where stress concentrations and microstructural changes favor crack initiation. In parallel, exposure to aggressive environments, particularly chloride-rich media such as marine conditions, can induce HE mechanisms. In this context, it is crucial to develop optimized welding techniques for high-strength steel wires, aiming to balance fatigue resistance and the reduction of HE. The choice of process should prioritize microstructural control, minimization of residual stresses, and low hydrogen uptake, ensuring reliable performance in critical 123 applications such as hydrogen transport and offshore environments. This study aims to determine a suitable welding process for high-carbon steel wires by comparing resistance welding and RFW in terms of fatigue resistance and HE. Materials and Methods High-carbon steel wire (0.7%C), 5.2 mm in diameter and manufactured by the drawing process, was studied. Optical emissio (...truncated)