The applicability of criteria of fracture mechanics for evaluating the hydrogen embrittlement of high-strength steels

1981 ◽  
Vol 16 (6) ◽  
pp. 532-537
Author(s):  
O. N. Romaniv ◽  
G. N. Nikiforchin ◽  
A. S. Krys'kiv
Keyword(s):  
Fracture Mechanics ◽  
Hydrogen Embrittlement ◽  
High Strength Steels ◽  
High Strength

Studies of SCC and Hydrogen Embrittlement of High Strength Alloys Using Fracture Mechanics Methods

2005 ◽  
Vol 482 ◽  
pp. 11-16 ◽  
Author(s):  
Wolfgang Dietzel ◽  
Michael Pfuff ◽  
Guido G. Juilfs
Keyword(s):  
Plastic Deformation ◽  
Fracture Mechanics ◽  
Hydrogen Embrittlement ◽  
Hydrogen Diffusion ◽  
High Strength Steels ◽  
High Strength ◽  
Constant Load ◽  
Rate Of Change ◽  
Extension Rate ◽  
Hydrogen Atoms

Fracture mechanics based test and evaluation techniques are used to gain insight into the phenomenon of stress corrosion cracking (SCC) and to develop guidance for avoiding or controlling SCC. Complementary to well known constant load and constant deflection test methods experiments that are based on rising load or rising displacement situations and are specified in the new ISO standard 7539 – Part 9 may be applied to achieve these goals. These are particularly suitable to study cases of SCC and hydrogen embrittlement of high strength steels, aluminium and titanium alloys and to characterise the susceptibility of these materials to environmentally assisted cracking. In addition, the data generated in such R-curve tests can be used to model the degradation of the material caused by the uptake of atomic hydrogen from the environment. This is shown for the case of a high strength structural steel (FeE 690T) where in fracture mechanics SCC tests on pre-cracked C(T) specimens a correlation between the rate of change in plastic deformation and the crack extension rate due to hydrogen embrittlement was established. The influence of plastic strain on the hydrogen diffusion was additionally studied by electrochemical permeation experiments. By modelling this diffusion based on the assumption that trapping of the hydrogen atoms takes place at trap sites which are generated by the plastic deformation, a good agreement was achieved between experimentally obtained data and model predictions.

scholarly journals Quantitative tests revealing hydrogen enhanced dislocation motion in α-iron

2021 ◽  
Author(s):  
Long-Chao Huang ◽  
Dengke Chen ◽  
De-Gang Xie ◽  
Suzhi Li ◽  
Ting Zhu ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
High Strength Steels ◽  
High Strength ◽  
Dislocation Motion ◽  
Atomistic Simulations ◽  
Vacuum Degassing ◽  
Nucleation Barrier ◽  
Free Behavior ◽  
Individual Dislocation ◽  
Energy Transportation

Abstract Hydrogen embrittlement jeopardizes the use of high-strength steels as critical load-bearing components in energy, transportation, and infrastructure applications. However, our understanding of hydrogen embrittlement mechanism is still obstructed by the uncertain knowledge of how hydrogen affects dislocation motion, due to the lack of quantitative experimental evidence. Here, by studying the well-controlled, cyclic, bow-out movements of individual screw dislocations, the key to plastic deformation in α-iron, we find that the critical stress for initiating dislocation motion in a 2 Pa electron-beam-excited H2 atmosphere is 27~43% lower than that under vacuum conditions, proving that hydrogen lubricates screw dislocation motion. Moreover, we find that aside from vacuum degassing, dislocation motion facilitates the de-trapping of hydrogen, allowing the dislocation to regain its hydrogen-free behavior. Atomistic simulations reveal that the observed hydrogen-enhanced dislocation motion arises from the hydrogen-reduced kink nucleation barrier. These findings at individual dislocation level can help hydrogen embrittlement modelling in steels.

Role of elongated MnS inclusions in hydrogen embrittlement of high-strength steels

Metal Science ◽  
1982 ◽  
Vol 16 (12) ◽  
pp. 543-554 ◽  
Author(s):  
T. V. Venkatasubramanian ◽  
T. J. Baker
Keyword(s):  
Hydrogen Embrittlement ◽  
High Strength Steels ◽  
High Strength

Some Fracture Mechanics Correlations

1968 ◽  
Vol 10 (4) ◽  
pp. 329-336
Author(s):  
L. P. Pook
Keyword(s):  
Mechanical Properties ◽  
Fracture Mechanics ◽  
Tensile Test ◽  
High Strength Steels ◽  
High Strength ◽  
Gauge Length ◽  
Published Data ◽  
Square Root ◽  
Beryllium Copper ◽  
Reduction Of Area

The results of tests on two high-strength steels, beryllium copper and perspex, together with some published data on high-strength steels were examined to see whether there was any relationship between the fracture mechanics parameter K1C and conventional mechanical properties. It was found that for steels and beryllium copper a correlation appeared to exist between K1C and the zero gauge length strain (= Z/(1 - Z) where Z is the reduction of area measured in a tensile test). It was also found that for constant, K1C was proportional to the square root of Young's modulus. The correlation band for steels was too wide for K1C to be estimated accurately from.

Techniques for investigation of hydrogen embrittlement of advanced high strength steels

2018 ◽  
Vol 36 (5) ◽  
pp. 413-434 ◽  
Author(s):  
Darya Rudomilova ◽  
Tomáš Prošek ◽  
Gerald Luckeneder
Keyword(s):  
Hydrogen Embrittlement ◽  
Secondary Ion Mass Spectrometry ◽  
High Strength Steels ◽  
Thermal Desorption Spectroscopy ◽  
High Strength ◽  
Atmospheric Conditions ◽  
Kelvin Probe ◽  
Advanced High Strength Steels ◽  
Scanning Kelvin Probe ◽  
Atmospheric Exposure

AbstractProduction volumes of advanced high strength steels (AHSS) are growing rapidly due to material and energy savings they provide in a number of application areas. In order to use their potential fully, it is necessary to minimize any danger of unexpected failures caused by hydrogen embrittlement. It is possible only if deeper understanding of underlying mechanisms is obtained through further research. Besides description of main grades of AHSS and mechanisms of HE, this paper reviews available tools for determination of hydrogen content and susceptibility to HE focusing on atmospheric conditions. Techniques such as slow strain rate testing, constant load testing, electrochemical permeation technique, scanning Kelvin probe and scanning Kelvin probe force microscopy have already been used to study the effect of hydrogen entered under atmospheric exposure conditions. Nanoindentation, hydrogen microprint technique, thermal desorption spectroscopy, Ag decoration or secondary ion mass spectrometry can be also conducted after atmospheric exposure.

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