Hydrogen accelerated fatigue crack growth of friction stir welded X52 steel pipe. (16th February 2017)

• Record Type: Journal Article
• Authors: Ronevich, J.A.; Somerday, B.P.; Feng, Z.
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 7(2017)
• Page Start: 4259
• Page End: 4268
• Publication Date: 2017-02-16
• Subjects: Hydrogen embrittlement -- Friction stir weld -- Hydrogen assisted cracking -- Fatigue crack growth rate; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.10.153
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Friction stir welded steel pipelines were tested in high pressure hydrogen gas to examine the effects of hydrogen accelerated fatigue crack growth. Fatigue crack growth rate (da/dN) vs. stress-intensity factor range (ΔK) relationships were measured for an X52 friction stir welded pipe tested in 21 MPa hydrogen gas at a frequency of 1 Hz and R = 0.5. Tests were performed on three regions: base metal (BM), center of friction stir weld (FSW), and 15 mm off-center of the weld. For all three material regions, tests in hydrogen exhibited accelerated fatigue crack growth rates that exceeded an order of magnitude compared to companion tests in air. Among tests in hydrogen, fatigue crack growth rates were modestly higher in the FSW than the BM and 15 mm off-center tests. Select regions of the fracture surfaces associated with specified ΔK levels were examined which revealed intergranular fracture in the BM and 15 mm off-center specimens but an absence of intergranular features in the FSW specimens. The X52 friction stir weld and base metal tested in hydrogen exhibited fatigue crack growth rate relationships that are comparable to those for conventional arc welded steel pipeline of similar strength found in the literature. Highlights: Hydrogen accelerated fatigue crack growth of friction stir welded pipeline examined. In-situ fatigue crack growth rates measured in 21 MPa H2 gas at 1 Hz. Friction stir weld exhibited comparable H2 fatigue performance to arc welded pipe.