Exploring the use of neutrons to detect hydrogen embrittlement in high strength steel

2021 ◽  
pp. 1-10
Author(s):  
Sjoerd Roorda ◽  
Pat Clancy ◽  
Jonathan Bellemare ◽  
Simon Laliberté-Riverin
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Concentration ◽  
Bragg Peak ◽  
Neutron Radiography ◽  
High Strength ◽  
High Hydrogen ◽  
Angle Scattering ◽  
The Difference ◽  
Non Destructive ◽  
Reference Samples

With the aim of exploring neutron techniques for the non-destructive detection of hydrogen in embrittled steel, three sets of steel samples were studied with neutron scattering: Ni coated, Cd coated, and Cr coated. Each set contained a non-embrittled or low-hydrogen concentration reference and one or two embrittled and high-hydrogen concentration samples. It is observed that the incoherent scattering, when normalized by the intensity of the Bragg peak, is significantly higher for high-hydrogen concentration or embrittled samples than in the reference. Although the difference is small, this represents a non-destructive technique of detecting hydrogen embrittlement. Neutron radiography, and inelastic or small-angle scattering could not distinguish between embrittled and reference samples.

Diffusion of Hydrogen in Titanium-Vanadium Alloys

2005 ◽  
Vol 237-240 ◽  
pp. 340-345 ◽  
Author(s):  
Hans Jürgen Christ ◽  
S. Schroers ◽  
F.H.S. dos Santos
Keyword(s):  
Diffusion Coefficient ◽  
Titanium Alloys ◽  
Hydrogen Concentration ◽  
Hydrogen Diffusion ◽  
High Strength ◽  
Vanadium Concentration ◽  
Vanadium Alloys ◽  
High Hydrogen ◽  
Hydrogen Diffusion Coefficient ◽  
Diffusion Of Hydrogen

β–titanium alloys are very attractive materials for many applications because they combine low density, high strength and excellent corrosion resistance. The available data indicate a much higher hydrogen diffusion coefficient in β–titanium alloys as compared to α and α + β alloys. In order to predict the range of applicability of β–titanium alloys in environments, which release hydrogen, the hydrogen diffusion coefficient (DH) needs to be known quantitatively. In the framework of this study the value of DH was determinated on samples, which were electrochemically hydrogen charged. Long thin rods were used as samples and charged in such a way that high hydrogen concentrations were obtained in one half of the length of the specimens, while the other half was kept virtually unaffected. After charging, the rods were annealed enabling hydrogen to diffuse. Hydrogen concentration profiles were experimentally determined and evaluated on the basis of the Matano technique, in order to reveal any effect of concentration on DH. The experiments were carried out on β–titanium alloys of the binary Ti–V system. The concentration range of vanadium in the alloys studied was selected in such a way that it represents the compositions commonly found in commercial alloys. The results show that the effect of hydrogen concentration on DH is negligible and that DH increases with the vanadium concentration.

Hydrogen Embrittlement Resistance of High Strength 9260 Bar Steel Heat Treated by Quenching and Partitioning

2021 ◽  
Author(s):  
E. Hoyt ◽  
E. De Moor ◽  
K.O. Findley
Keyword(s):  
Hydrogen Embrittlement ◽  
Carbon Content ◽  
Hydrogen Concentration ◽  
Retained Austenite ◽  
Volume Fraction ◽  
High Strength ◽  
Quenching And Partitioning ◽  
Quench Temperature ◽  
Embrittlement Resistance ◽  
Hydrogen Embrittlement Resistance

Abstract The influence of microstructure on hydrogen embrittlement of high strength steels for fastener applications is explored in this study. Space limiting applications in areas such as the automotive or agricultural industries provide a need for higher strength fasteners. Albeit, hydrogen embrittlement susceptibility typically increases with strength. Using a 9260 steel alloy, the influence of retained austenite volume fraction in a martensitic matrix was evaluated with microstructures generated via quenching and partitioning. X-ray diffraction and scanning electron microscopy were used to assess the influence of retained austenite in the matrix with different quenching parameters. The quench temperatures varied from 160 °C up to 220 °C, and a constant partitioning temperature of 290 °C was employed for all quench and partitioned conditions. The target hardness for all testing conditions was 52-54 HRC. Slow strain rate tensile testing was conducted with cathodic hydrogen pre-charging that introduced a hydrogen concentration of 1.0-1.5 ppm to evaluate hydrogen embrittlement susceptibility of these various microstructures. The retained austenite volume fraction and carbon content varied with the initial quench temperature. Additionally, the lowest initial quench temperature employed, which had the highest austenite carbon content, had the greatest hydrogen embrittlement resistance for a hydrogen concentration level of 1.0-1.5 ppm.

Characterization of the Effect of Notch Bluntness on Hydrogen Embrittlement and Fracture Behavior Using FE Analyses

2015 ◽  
Author(s):  
Jun-Young Jeon ◽  
Nicolas O. Larrosa ◽  
Young-Ryun Oh ◽  
Yun-Jae Kim ◽  
Robert A. Ainsworth
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Concentration ◽  
Fracture Behavior ◽  
Hydrogen Diffusion ◽  
High Strength ◽  
Ductile Damage ◽  
Diffusion Analysis ◽  
As Stress ◽  
Damage Simulation

This paper introduces a method to characterize the effect of notch bluntness on hydrogen embrittlement for high strength structural steel, FeE 690T, C(T) specimens. Hydrogen concentration depending on notch radius is assessed via finite element (FE) hydrogen diffusion analysis already developed and validated by the authors. Reduction in fracture toughness, KIC or JIC, due to hydrogen embrittlement is evaluated by means of a coupled hydrogen diffusion-ductile damage analysis. The ductile damage simulation used in this study is based on the model known as ‘stress-modified fracture strain model’. Tensile properties and fracture strains are modified according to the level of hydrogen concentration in the simulation and its effect on the fracture behavior of the specimen is simulated for different notch radii.

STUDY OF HOMOGENEITY, POROSITY AND INTERNAL DEFECTS IN AERATED AND EPS AGGREGATE POLY BRICKS USING NEUTRON RADIOGRAPHY TECHNIQUE

2015 ◽  
Vol 7 (2) ◽  
pp. 1428-1439
Author(s):  
Khurshed Alam ◽  
Md. Sayeedur Rahman ◽  
Md. Mostafizur Rahman ◽  
S. M. Azaharul Islam
Keyword(s):  
Optical Density ◽  
Neutron Radiography ◽  
Density Variation ◽  
Expanded Polystyrene ◽  
Elemental Distribution ◽  
Non Destructive Testing ◽  
Internal Defects ◽  
Destructive Testing ◽  
Radiographic Images ◽  
Non Destructive

A powerful non-destructive testing (NDT) technique is adopted to study the internal defects and elemental distribution/homogeneity and porosity of aerated brick and EPS aggregate poly brick samples. In the present study the internal defects like homogeneity, porosity, elemental distribution, EPS aggregate and aerator distributor in the test samples have been observed by the measurement of gray value/optical density of the neutron radiographic images of these samples. From this measurement it is found that the neutron intensity/optical density variation with the pixel distance of the AOI of the NR images in both expanded polystyrene (EPS) aggregate poly brick and aerated brick samples comply almost same in nature with respect to the whole AOI but individually each AOI shows different nature from one AOI to another and it confirms that the elemental distribution within a AOI is almost homogeneous. Finally it was concluded that homogeneity, elemental distribution in the EPS aggregate poly brick sample is better than that of the aerated brick sample. 

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