The effect of hydrogen on the fatigue life of Ni–Cr–Mo steel envisaged for use as a storage cylinder for a 70MPa hydrogen station (original) (raw)
Related papers
Engineering Fracture Mechanics, 2011
Experiments to investigate the effect of hydrogen pressure and test frequency on the fatigue crack growth properties of a Ni-Cr-Mo steel for the storage cylinder of a 70 MPa hydrogen storage station were conducted. Compact tension specimens were cut out from the storage cylinder. The crack growth properties obtained in hydrogen gas were compared with those obtained in air. Higher hydrogen pressures and lower loading frequencies lead to faster crack growth. However, there is an upper limit to the acceleration of the fatigue crack growth rate in hydrogen gas, which can be used for the design of the hydrogen cylinder. The effect of long and large inclusions present in the steel was also verified. The observations carried out on specimen fracture surfaces showed that the low population of inclusions did not influence the fatigue crack growth rate.
Mathematical Analyses of Effect of Hydrogen on Fatigue Behaviour of Four Stainless Steels
2014
Fatigue in stainless steel-candidates for hydrogen storage and infrastructure is described mathematically at different loading conditions. The investigated steels are: EN10095 1.4301, EN10095 1.4401, EN10095 1.4404 and EN10095 1.4002. All the tests are carried out under tension-compression fatigue at different loads and a stress ratio R = −1. Specimens are machined in hour-glass shape with artificial hole from which initial cracks start their propagation. For finding the effect of hydrogen on fatigue behaviour of investigated steels, the specimens are divided into two groups: of hydrogen charged and uncharged ones. The obtained fatigue data of each steel are presented in plots “Crack length Number of cycles” and “Fatigue crack growth rate – Crack length”. A mathematical model is found for the data in the presentation “Fatigue crack growth rate – Crack length”. The model consists of double-parabolic-linear-curve for all steels, which makes it possible to prognosticate their fatigue b...
Hydrogen effects on low cycle fatigue of high strength steels
Materials Science and Technology, 2013
Hydrogen absorption occurs during steelmaking processes and causes detriment on mechanical properties, such as plasticity, fatigue strength and tensile strength, among others. The main purpose of the present paper is to study the hydrogen effects on the low cycle fatigue behaviour of a high strength steel, resulphurised and microalloyed. Before the cyclic tests, samples are cathodically charged using a H 2 SO 4 acid solution. In some samples, poisons are added. The flow stress evolution during cycling was studied by analysing the so called 'back' and 'friction' stresses derived from the hysteresis loops. Fatigued specimens were observed through scanning electron microscopy and transmission electron microscopy. Additionally, the metallographic technique known as 'silver decoration' allows evaluation of the hydrogen distribution in the structure by applying energy dispersive analysis. The higher stress levels and cyclic softening rates exhibited by hydrogen charged samples in comparison with uncharged ones are related with the friction stress behaviour. The hydrogen is found mainly associated with MnS inclusions.
Analysis of fatigue behaviour of stainless steels under hydrogen influence.PDF
Three stainless steels -ASTM 304, 316 and 316L -used in hydrogen utilization equipment are under investigation at conditions of tension-compression, rotating-bending and fretting fatigue. Fatigue tests are carried out with hydrogen charged and uncharged specimens. Hydrogen charging includes cathodic type of charging and exposure to high pressure hydrogen gas. The experiments under rotating bending and tensioncompression fatigue are conducted under different frequencies in three different laboratories: at . The fretting fatigue tests are presented by The HYDROGENIUS Institute at Kyushu University, Japan. The obtained results are presented in Wöhler curves complemented by plots "Short fatigue crack length-Number of cycles" and "Tangential force coefficient-Stress amplitude". The found fatigue characteristics are analyzed and compared at different loading conditions, showing the best performance of Steel 316L.
On Factors Influencing Fatigue Process in Steel 316L Used in Hydrogen Energy Technologies
2014
Investigations of fatigue in steels exposed to hydrogen media is extremely important problem. In this work, an austenitic stainless steel ASTM 316L resistant to hydrogen destructive influence is examined. The experiments presented have used hydrogen charged and uncharged specimens and were carried out under rotating bending and tension-compression fatigue in three different laboratories: at The University of Chemical Technology and Metallurgy, Sofia, Bulgaria; at Sandia National Laboratory, California and The University of Tufts, Medford, Massachusetts, USA; The Institute Hydrogenous at Kyushu University, Japan. The results are presented in Wöhler curves complemented by „Short fatigue crack length – Number of cycles“ curves and „Frequency Lifetimes“ plots, and compared respectively.
Anomalies in hydrogen enhanced fatigue of a high strength steel
International Journal of Fatigue, 2014
Fatigue crack growth for an HSLA steel was studied with in situ hydrogen charging. The hydrogen effect was highest at low DK values. The anomalies in hydrogen effect were found in the relative insensitivity of the crack growth rates to DK in a decreasing DK test protocol, and in the distinct differences of the crack growth rates for different loading protocols. These anomalies are explained by the hydrogen availability at the crack tip as a function of the test parameters. A ''t'' and ''DK'' based parameter was found to be universally applicable for hydrogen enhanced fatigue irrespective of loading protocol.
Application of a Model of Hydrogen-Assisted Fatigue Crack Growth in 4130 Steel
2017
In this work, we applied a finite element model to predict the cyclic lifetime of 4130 steel cylinders under the influence of hydrogen. This example is used to demonstrate the efficacy of a fatigue crack growth (FCG) model we have developed. The model was designed to be robust and incorporate features of stress-assisted hydrogen diffusion, large-scale plasticity, hydrogen gas pressure, loading frequency, and effects of microstructure. The model was calibrated to the 4130 steel material by use of tensile tests and experimental FCG results of a compact tension specimen. We then used the model to predict the hydrogenassisted FCG rate and cycle life of a pressurized cylinder with a deliberate initial thumbnail crack. The results showed good correlation to the cyclic lifetime results of 4130 pressurized cylinders found in the literature.
On the influence of internal hydrogen of fatigue thresholds of HSLA steel
Scripta Metallurgica, 1983
Environmental effects on fatigue strength, crack initiation and crack propagation of steels have been traditionally characterized in terms of classical hydrogen embrittlement or metal dissolution processes (1-3). However, recent results on the effect of gaseous environments at or near the fatigue threshold stress intensity have shown otherwise (4-6). The results of Suresh, Moss and Ritchie (4) on low strength steels have indicated that gaseous hydrogen has two distinct regimes; (1) above growth rates of 10-8 m/cycle where an abrupt acceleration in crack growth occurs at an a~proximately constant maximum stress intensity, KmTax , (ii) near-threshold below 5 x I0-~ m/cycles where growth rates in hydrogen may be two orders of magnitude higher than in air. The threshold stress intensity is also lower in hydrogen. The higher growth rate regime shows a dependence on frequency and R ratio. There is also a change in the fracture mode from predominantly transgranular in air and hydrogen below K T to predominantly intergranular, characteristic of hydrogen enhanced max crack growth, above K T. However, in the near threshold regime, despite the accelerated max crack growth and lower thresholds, no evidence of a frequency effect and little difference in the fracture mechanism in air and hydrogen were found. The acceleration due to hydrogen is limited to low R ratios. At high R ratios, R ~ 0.75, the results in hydrogen and air are identical and the hydrogen effects appear to be irreversible (5). Furthermore, testing in inert gaseous environment, dry air, argon and helium showed similar increases in crack growth rate and lower threshold values at low R ratios (5,6). The near-threshold results have been explained in terms of crack closure as induced by the corrosion products (5-7).