Constant-load delayed fracture test of atmospherically corroded high strength steels

2011 ◽  
Vol 257 (19) ◽  
pp. 8275-8281 ◽  
Author(s):  
Eiji Akiyama ◽  
Katsuhiro Matsukado ◽  
Songjie Li ◽  
Kaneaki Tsuzaki
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Constant Load ◽  
Fracture Test ◽  
Delayed Fracture

Hydrogen effects on fracture of high-strength steels with different micro-alloying

2015 ◽  
Vol 33 (6) ◽  
pp. 515-527 ◽  
Author(s):  
Olga Todoshchenko ◽  
Yuriy Yagodzinskyy ◽  
Valentina Yagodzinska ◽  
Tapio Saukkonen ◽  
Hannu Hänninen
Keyword(s):  
Chemical Composition ◽  
Electron Backscatter Diffraction ◽  
High Strength Steels ◽  
Thermal Desorption Spectroscopy ◽  
High Strength ◽  
Constant Load ◽  
Carbon Steels ◽  
Hydrogen Induced Cracking ◽  
Load Tests ◽  
Backscatter Diffraction

AbstractConstant load tests of high-strength carbon steels with different micro-alloying using strengths in the range of 1000–1400 MPa were performed at ambient temperature under continuous electrochemical hydrogen charging. Hydrogen markedly affects delayed fracture of all the studied steels. Fractography of the studied steels shows that fracture mechanism depends on the chemical composition of the studied steels and hydrogen-induced cracking exhibits intergranular or transgranular character occurring often in the form of hydrogen flakes. The size and chemical composition of non-metallic inclusions are analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Hydrogen-induced cracking initiates at TiN/TiC particles in steels with Ti alloying. Crack paths are studied with electron backscatter diffraction mapping to analyze crack initiation and growth. The thermal desorption spectroscopy method is used to analyze the distribution of hydrogen in the trapping sites. The mechanisms of hydrogen effects on fracture of high-strength steels are discussed.

scholarly journals Delayed Fracture of High Strength Steels

1994 ◽  
Vol 80 (9) ◽  
pp. 679-684 ◽  
Author(s):  
Shinsaku MATSUYAMA
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Delayed Fracture

scholarly journals Comparison of Constant Load, SSRT and CSRT Methods for Hydrogen Embrittlement Evaluation Using Round Bar Specimens of High Strength Steels

2014 ◽  
Vol 100 (10) ◽  
pp. 1298-1305 ◽  
Author(s):  
Tetsushi Chida ◽  
Yukito Hagihara ◽  
Eiji Akiyama ◽  
Kengo Iwanaga ◽  
Shusaku Takagi ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
High Strength Steels ◽  
High Strength ◽  
Constant Load ◽  
Round Bar

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.

Application of Local Approach to Hydrogen Embrittlement Fracture Evaluation of High Strength Steels

2007 ◽  
Vol 539-543 ◽  
pp. 2155-2161 ◽  
Author(s):  
Shusaku Takagi ◽  
Satoshi Terasaki ◽  
Kaneaki Tsuzaki ◽  
Tadanobu Inoue ◽  
Fumiyoshi Minami
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Content ◽  
Fracture Property ◽  
Martensitic Steel ◽  
High Strength Steels ◽  
High Strength ◽  
New Method ◽  
Local Approach ◽  
Delayed Fracture ◽  
Ultra High Strength Steel

A new method for evaluating the hydrogen embrittlement (HE) susceptibility of ultra high strength steel was studied in order to propose a new method for assessing the delayed fracture property. The material used was 1400MPa tempered martensitic steel with the chemical composition 0.40C-0.24Si-0.81Mn-1.03Cr-0.16Mo(mass%). The local approach originally used for evaluating the brittle fracture property was applied to HE susceptibility assessment after modifying the method to include the effect of hydrogen content. Critical HE data used in the modified local approach was obtained by a stepwise test in which alternating processes of stress increase and stress holding were repeated until the specimen fractured. The specimen used in the stepwise test was 10 mm in diameter and the stress concentration factor was 4.9. Assessment of HE susceptibility for specimens with other dimensions entailed the use of a critical hydrogen content for failure, Hc, representing the maximum hydrogen content among the unfractured specimens in the HE test with constant loading. Matters to be noted for obtaining the material parameters are discussed.

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