Strain rate and hydrogen effects on crack growth from a notch in a Fe-high-Mn steel containing 1.1 wt% solute carbon

Najam, Hina; Koyama, Motomichi; Bal, Burak; Akiyama, Eiji; Tsuzaki, Kaneaki

doi:10.1016/j.ijhydene.2019.10.227

Cited by 23 publications

(3 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the specimens that included a girth weld, a notch with a radius of 4 mm and a depth of 1 mm was machined to promote fracture in the weld region. Notches create zones of high hydrostatic tensile stress, high stress triaxialities and strain localisation, which increase HE susceptibility locally and adversely affect fracture behaviour [25,40,41]. By using a blunt notch, a reduction in the cross-section is achieved that raises the stress in the WM to compensate for the higher strength levels than the BM without creating regions of excessive localisation of stress and strain that could significantly influence HE behaviour.…”

Section: Methodsmentioning

confidence: 99%

In-Situ Hollow Sample Setup Design for Mechanical Characterisation of Gaseous Hydrogen Embrittlement of Pipeline Steels and Welds

Boot

Riemslag

Reinton

et al. 2021

Metals

View full text Add to dashboard Cite

This work discusses the design and demonstration of an in-situ test setup for testing pipeline steels in a high pressure gaseous hydrogen (H2) environment. A miniature hollow pipe-like tensile specimen was designed that acts as the gas containment volume during the test. Specific areas of the specimen can be forced to fracture by selective notching, as performed on the weldment. The volume of H2 used was minimised so the test can be performed safely without the need of specialised equipment. The setup is shown to be capable of characterising Hydrogen Embrittlement (HE) in steels through testing an X60 pipeline steel and its weldment. The percentage elongation (%El) of the base metal was found to be reduced by 40% when tested in 100 barg H2. Reduction of cross-sectional area (%RA) was found to decrease by 28% and 11% in the base metal and weld metal, respectively, when tested in 100 barg H2. Benchmark test were performed at 100 barg N2 pressure. SEM fractography further indicated a shift from normal ductile fracture mechanisms to a brittle transgranular (TG) quasi-cleavage (QC) type fracture that is characteristic of HE.

show abstract

Section: Methodsmentioning

confidence: 99%

In-Situ Hollow Sample Setup Design for Mechanical Characterisation of Gaseous Hydrogen Embrittlement of Pipeline Steels and Welds

Boot

Riemslag

Reinton

et al. 2021

Metals

View full text Add to dashboard Cite

show abstract

“…Hydrogen diffusion behavior has been studied through electrochemical hydrogen permeation (EHP) [4][5][6][7][8][13][14][15][16][17][18][19][20] to understand physical variables such as solubility and diffusivity of H in steels. In the last decades, numerous authors have performed different mechanical tests with notched specimens in the presence of H 9,10,[21][22][23][24][25] to address the critical conditions of hydrostatic stress and hydrogen concentration. In general, it has been observed that HE increases when the stress triaxiality conditions are higher 25 .…”

Section: Introductionmentioning

confidence: 99%

Effects of Hydrogen in Stress Triaxiality of API 5L X70 Steel

et al. 2023

View full text Add to dashboard Cite

Hydrogen embrittlement (HE) in API 5L X70 steel was investigated by testing notched and unnotched uniaxial tensile specimens and single-edge tension specimen, SE(T). Apparent hydrogen diffusivity (D app = 1.4 x 10 -10 m 2 /s) and solubility (S app = 4.9 mol H/m 3 ) were determined by electrochemical hydrogen permeation tests. Through mathematical fitting, it was possible to separate the strong traps present at the beginning of the first permeation curve (φ = 0.43 mol H/m 3 ). Uniaxial tensile tests showed a loss of ductility of up to 33% in the hydrogenated condition. Fracture mechanics tests exhibited a toughness decrease of 14% after exposure to hydrogen. The high resistance to HE was presented suggesting that these microalloyed steels can solubilize hydrogen in the matrix with low segregation, reducing the impact on embrittlement. A mix of ductile and quasi-cleavage fracture was observed in the hydrogenated samples with an increased stress triaxiality.

show abstract

“…This occurrence is generally explained by a lack of void growth process and reduced crack growth resistance [27]. Except for dimples, ductile-tearing and brittle-like fractures were also observed in a high-martensite dual-phase (HMDP) steel within the DSA range [28]. In addition, the dislocation-carbon interaction could induce intergranular cracking and reduce the ductility in high-Mn steel [29].…”

Section: Introductionmentioning

confidence: 99%

Stress-state dependence of dynamic strain aging: Thermal hardening and blue brittleness

Liu

Lian

2021

Int J Miner Metall Mater

View full text Add to dashboard Cite

This study aims to discover the stress-state dependence of the dynamic strain aging (DSA) effect on the deformation and fracture behavior of high-strength dual-phase (DP) steel at different deformation temperatures (25–400°C) and reveal the damage mechanisms under these various configurations. To achieve different stress states, predesigned specimens with different geometric features were used. Scanning electron microscopy was applied to analyze the fracture modes (e.g., dimple or shear mode) and underlying damage mechanism of the investigated material. DSA is present in this DP steel, showing the Portevin-Le Chatelier (PLC) effect with serrated flow behavior, thermal hardening, and blue brittleness phenomena. Results show that the stress state contributes distinctly to the DSA effect in terms of the magnitude of thermal hardening and the pattern of blue brittleness. Either low stress triaxiality or Lode angle parameter promotes DSA-induced blue brittleness. Accordingly, the damage mechanisms also show dependence on the stress states in conjunction with the DSA effect.

show abstract

Strain rate and hydrogen effects on crack growth from a notch in a Fe-high-Mn steel containing 1.1 wt% solute carbon

Cited by 23 publications

References 53 publications

In-Situ Hollow Sample Setup Design for Mechanical Characterisation of Gaseous Hydrogen Embrittlement of Pipeline Steels and Welds

In-Situ Hollow Sample Setup Design for Mechanical Characterisation of Gaseous Hydrogen Embrittlement of Pipeline Steels and Welds

Effects of Hydrogen in Stress Triaxiality of API 5L X70 Steel

Stress-state dependence of dynamic strain aging: Thermal hardening and blue brittleness

Contact Info

Product

Resources

About