The Role of Welding Parameters in Hydrogen Embrittlement Mitigation: A Case Study in Steel

Abstract

This research investigates the mitigation of hydrogen embrittlement in steel, focusing on the effects of metallurgical hydrogen and the efficacy of various reduction techniques. Key findings demonstrate that vacuum treatment during steel casting combined with thermal treatment significantly lowers hydrogen content, enhancing steel's resistance to embrittlement. Welding processes differ in susceptibility to hydrogen-induced cracking, with submerged arc welding (SAW) showing the least and shielded metal arc welding (SMAW) the most susceptibility. Employing multipass welding, along with preheating and post-weld heat treatments, effectively minimizes hydrogen-related cracking by promoting even hydrogen distribution and desorption. The study highlights the successful application of fluoride-ion-containing welding fluxes, such as CaF2 and KF, to reduce weld hydrogen levels through chemical reactions. Furthermore, the choice of welding parameters, particularly the arc voltage, substantially impacts the hydrogen concentration in the welds. Additionally, the incorporation of hydrogen-binding elements such as yttrium significantly reduces the level of free hydrogen, thereby enhancing resistance to hydrogen corrosion. The research underlines the need for selecting appropriate welding methods and parameters to effectively reduce the adverse effects on welded joints. In conclusion, optimizing vacuum and thermal treatments, along with developing innovative welding materials, is imperative to control hydrogen content, crucial to the longevity and reliability of steel products in hydrogen-sensitive applications such as the oil and gas sector.