scholarly journals Defect size dependence on threshold stress intensity for high-strength steel with internal hydrogen

2013 ◽  
Vol 36 (9) ◽  
pp. 836-850 ◽  
Author(s):  
Y. Murakami ◽  
H. Matsunaga ◽  
A. Abyazi ◽  
Y. Fukushima
Keyword(s):  
Stress Intensity ◽  
High Strength Steel ◽  
Threshold Stress ◽  
Size Dependence ◽  
High Strength ◽  
Defect Size ◽  
Threshold Stress Intensity ◽  
Internal Hydrogen

Evaluation of threshold stress intensity in high strength hydrogen charged steel in low strain rate tension tests

1993 ◽  
Vol 9 (11) ◽  
pp. 1009-1013 ◽  
Author(s):  
B. Ule ◽  
F. Vodopivec ◽  
L. Vehovar ◽  
J. Žvokelj ◽  
L. Kosec
Keyword(s):  
Stress Intensity ◽  
Strain Rate ◽  
Threshold Stress ◽  
High Strength ◽  
Threshold Stress Intensity ◽  
Tension Tests ◽  
Low Strain Rate

Evaluation of the Internal Hydrogen-Induced Threshold Stress Intensity Factor in 2.25Cr-1Mo Steels Determined by the Offset Potential Drop Method

2017 ◽  
Author(s):  
Shinji Konosu ◽  
Takehiro Inoue ◽  
Yoshiaki Murakami
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Hydrogen Embrittlement ◽  
Intensity Factor ◽  
Threshold Stress ◽  
Potential Drop ◽  
Threshold Stress Intensity ◽  
Drop Method ◽  
Internal Hydrogen ◽  
Threshold Stress Intensity Factor

The single specimen offset potential drop method has been applied to obtain the internal hydrogen-induced threshold stress intensity factor KIH in Cr-Mo steels by using small-sized 12.7-mm-thick ASTM CT-specimens (1/2T-CT).The subcommittee on Hydrogen Embrittlement in the Material Division of the Japan Pressure Vessel Research Council (JPVRC) had been investigating internal hydrogen embrittlement by using 25.4mm thick compact tension specimens (1T-CT(1/2): B = 25.4mm, W = 25.4mm, 2H = 30.5mm), to enable an adequate supply of hydrogen from the uncracked region of the specimen near a crack tip to the crack tip zone during the experiment under normal atmospheric conditions. In the present study, tests were performed on 1/2T-CT specimens under a mixed load control and grip-displacement control aimed at achieving a reduction in the test execution time. It was found that the threshold stress intensity factors for the 1/2T-CT specimens exhibited virtually the same behavior as those obtained in the previous studies using the 1T-CT (1/2) specimens.

Engineering Relation for Dependence of Threshold Stress Intensity Factor for Delayed Hydride Cracking on Crack Orientation

2008 ◽  
Author(s):  
Douglas A. Scarth ◽  
Gordon K. Shek ◽  
Steven X. Xu
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Threshold Stress ◽  
Pressure Tube ◽  
Threshold Stress Intensity ◽  
Tube Material ◽  
Fuel Bundle ◽  
Threshold Stress Intensity Factor ◽  
Cold Worked

Delayed Hydride Cracking (DHC) in cold-worked Zr-2.5 Nb pressure tubes is of interest to the CANDU industry in the context of the potential to initiate DHC at an in-service flaw. Examples of in-service flaws are fuel bundle scratches, crevice corrosion marks, fuel bundle bearing pad fretting flaws and debris fretting flaws. To date, experience with fretting flaws has been favourable, and crack growth from an in-service fretting flaw has not been detected. However, postulated DHC growth from these flaws can result in severe restrictions on the allowable number of reactor Heatup/Cooldown cycles prior to re-inspection of the flaw, and it is important to reduce any unnecessary conservatism in the evaluation of DHC from the flaw. One method to reduce conservatism is to take credit for the increase in the isothermal threshold stress intensity factor for DHC initiation at a crack, KIH, as the flaw orientation changes from an axial flaw to a circumferential flaw in the pressure tube. This increase in KIH is due to the texture of the pressure tube material. An engineering relation that provides the value of KIH as a function of the orientation of the flaw relative to the axial direction in the pressure tube has been developed as described in this paper. The engineering relation for KIH has been validated against results from DHC initiation experiments on unirradiated cold-worked Zr-2.5 Nb pressure tube material.

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