scholarly journals Hydrogen Effects on Fatigue Crack Growth Rates in Pipeline Steel Welds

2016 ◽  
Author(s):  
Joe A. Ronevich ◽  
Brian P. Somerday
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Pipeline Steel ◽  
Hydrogen Gas ◽  
Friction Stir Weld ◽  
Friction Stir ◽  
Welding Processes ◽  
Crack Growth Rates

Fatigue crack growth rate (da/dN) versus stress intensity factor range (ΔK) relationships were measured for various grades of pipeline steel along with their respective welds in high pressure hydrogen. Tests were conducted in both 21 MPa hydrogen gas and a reference environment (e.g. air) at room temperature. Girth welds fabricated by arc welding and friction stir welding processes were examined in X65 and X52 pipeline grades, respectively. Results showed accelerated fatigue crack growth rates for all tests in hydrogen as compared to tests in air. Modestly higher hydrogen-assisted crack growth rates were observed in the welds as compared to their respective base metals. The arc weld and friction stir weld exhibited similar fatigue crack growth behavior suggesting similar sensitivity to hydrogen. A detailed study of microstructure and fractography was performed to identify relationships between microstructure constituents and hydrogen accelerated fatigue crack growth.

Fatigue crack growth rates of API X70 pipeline steel in a pressurized hydrogen gas environment

2013 ◽  
Vol 37 (5) ◽  
pp. 517-525 ◽  
Author(s):  
E. S. Drexler ◽  
A. J. Slifka ◽  
R. L. Amaro ◽  
N. Barbosa ◽  
D. S. Lauria ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Pipeline Steel ◽  
Hydrogen Gas ◽  
X70 Pipeline Steel ◽  
Gas Environment ◽  
Crack Growth Rates

Fracture and Fatigue Tolerant Steel Pressure Vessels for Gaseous Hydrogen

2010 ◽  
Author(s):  
Kevin A. Nibur ◽  
Chris San Marchi ◽  
Brian P. Somerday
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Maximum Load ◽  
Pressure Vessels ◽  
Hydrogen Gas ◽  
R Ratio ◽  
History Of ◽  
Crack Growth Rates

Fatigue crack growth rates and rising displacement fracture thresholds have been measured for a 4130X steel in 45 MPa hydrogen gas. The ratio of minimum to maximum load (R-ratio) and cyclic frequency was varied to assess the effects of these variables on fatigue crack growth rates. Decreasing frequency and increasing R were both found to increase crack growth rate, however, these variables are not independent of each other. Changing frequency from 0.1 Hz to 1 Hz reduced crack growth rates at R = 0.5, but had no effect at R = 0.1. When applied to a design life calculation for a steel pressure vessel consistent with a typical hydrogen trailer tube, the measured fatigue and fracture data predicted a re-inspection interval of nearly 29 years, consistent with the excellent service history of such vessels which have been in use for many years.

Characteristics of Corrosion Fatigue Crack Growth in Salt Water of Aluminum Alloys for Hydrogen Gas Containers

2013 ◽  
Author(s):  
Takeshi Ogawa ◽  
Yuki Sugiyama ◽  
Toshihiko Kanezaki ◽  
Noboru Hayashi
Keyword(s):  
Fatigue Crack ◽  
Aluminum Alloys ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Salt Water ◽  
Hydrogen Gas ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth ◽  
Crack Growth Rates

A hydrogen gas container is one of the critical components for fuel cell vehicles (FCV), which is expected for CO2-free personal transportation. In the early stage of commercial FCV, the major container structure will be a compressed hydrogen gas cylinder, which consists of metal or plastic linear with metal boss and carbon fiber reinforced plastics (CFRP). In order to choose an appropriate material for the metal boss and metal liner, corrosion resistance should be evaluated for various aspects such as corrosion fatigue crack growth (CFCG) and stress corrosion cracking (SCC) in the high pressure hydrogen as well as in salt water environment for the purpose of vehicle use. In the present study, CFCG characteristics were evaluated for several aluminum alloys in air and in salt waters with various concentrations. The results showed that the crack growth rates were accelerated in salt water for all the materials and their environmental sensitivities were compared. The concentrations of the salt water exhibited minor effect on the fatigue crack growth rates. These CFCG characteristics were compared with the corrosion test results based on the ISO 7866 Annex A [1]. A basic idea was proposed for the evaluation of compressed hydrogen gas containers and the important material properties were suggested.

scholarly journals Measurement of Fatigue Crack Growth Relationships in Hydrogen Gas for Pressure Swing Adsorber Vessel Steels

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Brian P. Somerday ◽  
Monica Barney
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Load Cycle ◽  
Hydrogen Gas ◽  
Stress Intensity Factor Range ◽  
Cycle Frequency ◽  
Pressure Swing ◽  
Crack Growth Rates

Hydrogen-assisted fatigue crack growth rates (da/dN) were measured for SA516 Grade 70 steel as a function of stress-intensity factor range (ΔK) and load-cycle frequency to provide life-prediction data relevant to pressure swing adsorber (PSA) vessels. For ΔK values up to 18.5 MPa m1/2, the baseline da/dN versus ΔK relationship measured at 1 Hz in 2.8 MPa hydrogen gas represents an upper bound with respect to crack growth rates measured at lower frequency. However, at higher ΔK values, baseline da/dN data must be corrected to account for modestly higher crack growth rates at the lower frequencies relevant to PSA vessel operation.

scholarly journals Optimizing Measurement of Fatigue Crack Growth Relationships for Cr-Mo Pressure Vessel Steels in Hydrogen Gas

2015 ◽  
Author(s):  
Brian Somerday ◽  
Paolo Bortot ◽  
John Felbaum
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Upper Bound ◽  
Growth Rates ◽  
Hybrid Approach ◽  
Hydrogen Gas ◽  
Design Life ◽  
Pressure Vessel Steels ◽  
Crack Growth Rates

The objective of this study was to explore an approach for measuring fatigue crack growth rates (da/dN) for Cr-Mo pressure vessel steels in high-pressure hydrogen gas over a broad cyclic stress intensity factor (ΔK) range while limiting test duration, which could serve as an alternative to the method prescribed in ASME BPVC VIII-3, Article KD-10. Fatigue crack growth rates were measured for SA-372 Grade J and 34CrMo4 steels in hydrogen gas as a function of ΔK, load-cycle frequency (f), and gas pressure. The da/dN vs. ΔK relationships measured for the Cr-Mo steels in hydrogen gas at 10 Hz indicate that capturing data at lower ΔK is valuable when these relationships serve as inputs into design-life analyses of hydrogen pressure vessels, since in this ΔK range crack growth rates in hydrogen gas approach rates in air. The da/dN vs. f data measured for the Cr-Mo steels in hydrogen gas at selected constant-ΔK levels demonstrate that crack growth rates at 10 Hz do not represent upper-bound behavior, since da/dN generally increases as f decreases. Consequently, although fatigue crack growth testing at 10 Hz can efficiently measure da/dN over a wide ΔK range, these da/dN vs. ΔK relationships at 10 Hz cannot be considered reliable inputs into design-life analyses. A possible hybrid approach to efficiently establishing the fatigue crack growth rate relationship in hydrogen gas without compromising data quality is to measure the da/dN vs. ΔK relationship at 10 Hz and then apply a correction based on the da/dN vs. f data. The reliability of such a hybrid approach depends on adequacy of the da/dN vs. f data, i.e., the data are measured at appropriate constant-ΔK levels and the data include upper-bound crack growth rates.

Measurements of Fatigue Crack Growth Rates of the Heat-Affected Zones of Welds of Pipeline Steels

2015 ◽  
Author(s):  
Andrew J. Slifka ◽  
Elizabeth S. Drexler ◽  
Robert L. Amaro ◽  
Damian S. Lauria ◽  
Louis E. Hayden ◽  
...  
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Growth Rates ◽  
Hydrogen Gas ◽  
Low Resistance ◽  
Crack Growth Rates

Pipelines are widely accepted to be the most economical method for transporting large volumes of hydrogen, needed to fuel hydrogen-powered vehicles. Some work has been previously conducted on the fatigue crack growth rates of base metals of pipeline materials currently in use for hydrogen transport and on pipeline materials that may be used in the future. However, welds and their heat-affected zones are oftentimes the source and pathway for crack initiation and growth. The heat-affected zones of welds can exhibit low resistance to crack propagation relative to the base metal or the weld itself. Microstructural irregularities such as chemical segregation or grain-size coarsening can lead to this low resistance. Therefore, in order to have adequate information for pipeline design, the microstructures of the heat-affected zones must be characterized, and their mechanical properties must be measured in a hydrogen environment. With that in mind, data on the fatigue crack growth rate is a critical need. We present data on the fatigue crack growth rate of the heat-affected zones for two girth welds and one seam weld from two API 5L X52 pipes. The materials were tested in hydrogen gas pressurized to 5.5 MPa and 34 MPa at a cyclic loading rate of 1 Hz, and an R ratio of 0.5.

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