Influence of Precracked Specimen Configuration and Starting Stress Intensity on the Stress Corrosion Cracking of 4340 Steel

2008 ◽  
pp. 80-80-18 ◽  
Author(s):  
WB Lisagor
Keyword(s):  
Stress Intensity ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Precracked Specimen ◽  
4340 Steel

Environmental Effects of Sulfur and Sulfur Compounds on the Resistance to Stress Corrosion Cracking of AISI 4340 Steel in Aqueous Chloride Solutions

CORROSION ◽  
1969 ◽  
Vol 25 (8) ◽  
pp. 342-344 ◽  
Author(s):  
A. TIRMAN ◽  
E. G. HANEY ◽  
PAUL FUGASSI
Keyword(s):  
Sodium Chloride ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Prior Treatment ◽  
Aisi 4340 Steel ◽  
Aqueous Sodium ◽  
4340 Steel ◽  
Resistance To Stress ◽  
Aisi 4340

Abstract The resistance to stress corrosion cracking of AISI 4340 steel foil in 0.6M aqueous sodium chloride, acidified to pH 1.5 with hydrochloric acid, is greatly decreased by prior treatment of the specimens for short periods of time with aqueous and nonaqueous solutions of sulfur, organic and inorganic sulfides, sulfur dioxides, and the inorganic salts of sulfurousand sulfuric acids. It is suggested that this prior treatment produces sulfided areas which are inhibitors of the combination of atomic hydrogen into molecular hydrogen. The decreased resistance to stress corrosion cracking is thus attributed to hydrogen embrittlement. If the stress corrosion cracking test is made in 0.6M aqueous sodium chloride, adjusted to an initial pH of 8, the effect of a prior sulfiding treatment is small. The formation of such sulfided areas in practice result from the exposure of 4340 steels to industrial atmospheres which may contain hydrogen sulfide, sulfur dioxide, and elemental sulfur.

The role of crack branching in stress corrosion cracking of aluminium alloys

2015 ◽  
Vol 33 (6) ◽  
pp. 443-454 ◽  
Author(s):  
Timothy L. Burnett ◽  
N.J. Henry Holroyd ◽  
Geoffrey M. Scamans ◽  
Xiaorong Zhou ◽  
George E. Thompson ◽  
...  
Keyword(s):  
Stress Intensity ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Aluminium Alloys ◽  
Compact Tension ◽  
Corrosion Cracking ◽  
Three Dimensions ◽  
Crack Branching ◽  
Test Procedures ◽  
The Many

AbstractStress corrosion cracks of all types are characterised by extensive crack branching, and this is frequently used as the key failure analysis characteristic to identify this type of cracking. For aluminium alloys, stress corrosion cracking (SCC) is almost exclusively an intergranular failure mechanism. For plate and extruded components, this had led to the development of test procedures using double cantilever beam and compact tension precracked specimens that rely on the pancake grain shape to constrain cracking, so that fracture mechanics can be applied to the analysis of stress intensity and crack velocity and the evolution of a characteristic performance curve. We have used X-ray computed tomography to examine in detail SCC in aluminium alloys in three dimensions for the first time. We have found that crack branching limits the stress intensity at the crack tip as the applied stress is shared amongst a number of cracks that are held together by uncracked ligaments. We propose that the plateau region observed in the v-K curve is an artefact due to crack branching, and at the crack tips of the many crack branches, cracking essentially occurs at constant K almost irrespective of the crack length. We have amplified the crack branching effect by examining a sample where the long axis of the pancake grains was inclined to the applied stressing direction. Our results have profound implications for the future use of precracked specimens for SCC susceptibility testing and the interpretation of results from these tests.

The Effect of Some Electrolytes on the Stress Corrosion Cracking of AISI 4340 Steel

CORROSION ◽  
1972 ◽  
Vol 28 (9) ◽  
pp. 340-344 ◽  
Author(s):  
H. R. BAKER ◽  
C. R. SINGLETERRY
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Ph Dependence ◽  
Corrosion Cracking ◽  
Alkaline Solutions ◽  
Poor Correlation ◽  
Time To Failure ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Aisi 4340

Abstract The effects of solutions of 16 different electrolytes on the stress corrosion cracking (SCC) of AISI 4340 steel U-bend specimens have been studied at various concentrations and at 25, 65, and 100 C (77, 149, and 212 F). Stresses were near the yield point of the alloy. In unbuffered solutions of neutral salts, there was poor correlation between time to failure and the initial or final pH of the solution. In strongly buffered solutions, there was a strong pH dependence; the time to failure in 10% NaCl increased about 100 fold between pH 4–5 and pH 7. Susceptibility to cracking increased moderately with the concentration of KNO3 solutions, but decreased with rising concentration of NaCl solutions. The cracking rate increased by 50% per 10 C for NaCl solutions. The rate increased 85% per 10 C for KNO3 solutions. KNO2 or NaNO2, dicyclohexylammonium nitrate, some K2CrO4 solutions and all alkaline solutions with a strong reserve of base inhibited SCC by factors of 10 to 100 times as compared with cracking in distilled H2O.

Threshold Stress Intensity for Stress Corrosion Cracking (KISCC) of a Magnesium Alloy in Physiological Environment

2011 ◽  
Vol 690 ◽  
pp. 487-490 ◽  
Author(s):  
Lokesh Choudhary ◽  
R.K. Singh Raman
Keyword(s):  
Stress Intensity ◽  
Magnesium Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Threshold Stress ◽  
Corrosion Cracking ◽  
Threshold Stress Intensity ◽  
Az91d Magnesium Alloy ◽  
Threshold Stress Intensity Factor ◽  
Circumferential Notch

Threshold stress intensity factor for stress corrosion cracking (KISCC) of AZ91D magnesium alloy in a simulated physiological environment has been determined using circumferential notch tensile (CNT) technique. Fracture surfaces of the tested specimens were analysed using scanning electron microscopy (SEM) in order to examine the features for SCC.

Sign in / Sign up

Export Citation Format

Share Document