Hydrogen induced blister cracking and mechanical failure in X65 pipeline steels. (13th August 2019)

• Record Type: Journal Article
• Authors: Singh, Vishal; Singh, Rajwinder; Arora, Kanwer Singh; Mahajan, Dhiraj K.
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 39(2019)
• Page Start: 22039
• Page End: 22049
• Publication Date: 2019-08-13
• Subjects: Hydrogen embrittlement -- Short fatigue crack -- Blister -- Pipeline steel; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.06.098
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The present work aims to investigate the role of hydrogen induced blisters cracking on degradation of tensile and fatigue properties of X65 pipeline steel. Both tensile and fatigue specimens were electrochemically charged with hydrogen at 20 mA/cm 2 for a period of 4 h. Hydrogen charging resulted in hydrogen induced cracking (HIC) and blister formation throughout the specimen surface. Nearly all the blisters formed during hydrogen charging showed blister wall cracking (BWC). Inclusions mixed in Al-Si-O were found to be the potential sites for HIC and BWC. Slow strain rate tensile (SSRT) test followed by fractographic analysis confirmed significant hydrogen embrittlement (HE) susceptibility of X65 steel. Short fatigue crack growth framework, on the other hand, specifically highlighted the role of BWC on accelerated crack growth in the investigated material. Coalescence of propagating short fatigue crack with BWC resulted in rapid increase in the crack length and reduced the number of cycles for crack propagation to the equivalent crack length. Highlights: Electrochemical hydrogen charging of X65 steel specimen led to blister formation throughout the surface. Oxide inclusions enriched with Al and Si in X65 steel are shown to be the most prominent sites for blister formation. Short fatigue crack growth framework highlighted the role of blister wall crack on accelerated crack growth in X65 steels.