Corrosion and Hydrogenation in Titanium Alloys: An Electrochemical Approach to the Ti-6Al-4V Alloy with Ruthenium Addition

• Grant number: 24/10695-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2025
• End date: August 31, 2027
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Guilherme Yuuki Koga
• Grantee: Hassan Asif
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Titanium and its alloys are highly valued in the offshore oil and gas industry for their exceptional corrosion resistance and specific strength. However, hydrogen embrittlement poses a significant challenge, restricting their broader application in corrosive environments such as seawater and hydrogen sulfide exposure. Understanding the mechanisms behind hydrogen embrittlement and assessing its susceptibility under various conditions-including temperature variations and cathodic protection levels-is crucial. The titanium alloys containing ruthenium is promising to endure demanding components but is still susceptible to hydrogen embrittlement. Damage to the protective polymer coating on these components and the loss of passivation can facilitate hydrogen ingress, leading to the formation of embrittling hydrides. Although there are several studies regarding the absorption and hydrogen effects on Ti-6Al-4V (Grade 23), research on Ti-6Al-4V-0.1Ru (Grade 29) is still scarce. While some reports suggest that the enhancement of the passive film of Ti alloys promoted by Ru-containing alloys potentially hinders hydrogen diffusion, other studies report conflicting results, indicating a higher susceptibility to hydrogen absorption in comparison with Ru-free titanium alloys. This research project aims to evaluate the corrosion resistance and electrochemical hydrogenation of Ti alloy grade 29 (Ti6Al4V + 0.01%Ru) baselined with the Ti alloy grade 23 (Ti6Al4V). The corrosion resistance of Ti alloys grades 23 and 29 will be performed in 0.6 M NaCl and boiling H2SO4 and HCl. The hydrogen ingress and the hydrates formation in acidic (H2SO4) and saline (0.6 M NaCl) will be rigorously assessed under cathodic protection at -1800 mVAg/AgCl for 7 days at room temperature. Given the growing use of Ti alloys in deep water oil and gas exploration, a comprehensive understanding of their corrosion resistance and hydrogenation is essential for ensuring a secure exploration.