Evaluating stress corrosion cracking behaviour of high strength AA7075-T651 aluminium alloy

2017 ◽  
Vol 26 (3-4) ◽  
pp. 105-112
Author(s):  
P. Prabhuraj ◽  
S. Rajakumar ◽  
A.K. Lakshminarayanan ◽  
V. Balasubramanian
Keyword(s):  
Aluminium Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Threshold Stress ◽  
High Strength ◽  
Constant Load ◽  
Corrosion Cracking ◽  
Time To Failure ◽  
Nacl Solution ◽  
Horizontal Type

AbstractThe objective of the present study is to determine the threshold stress level of stress corrosion cracking (SCC) in AA7075-T651 aluminium alloy by suitable experimentation. The test was carried out using a circumferential notch specimen in a horizontal-type constant load SCC setup in a 3.5 wt.% NaCl solution. The time to failure by SCC was determined at various loading conditions. The threshold stress of AA7075-T651 alloy was found to be 242 MPa in a 3.5 wt.% NaCl solution. The various regions of the fractured surface specimen such as machined notch, SCC region and final overload fracture area were examined using scanning electron microscopy (SEM) in order to identify the SCC mechanism.

Stress Corrosion Cracking Behavior of Uranium Alloys

CORROSION ◽  
1974 ◽  
Vol 30 (5) ◽  
pp. 181-189 ◽  
Author(s):  
W. F. CZYRKLIS ◽  
M. LEVY
Keyword(s):  
Fracture Mechanics ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Threshold Stress ◽  
Crack Extension ◽  
Corrosion Cracking ◽  
Nacl Solution ◽  
Cracking Behavior ◽  
Linear Elastic ◽  
Elastic Fracture

Abstract The stress corrosion cracking (SCC) behavior of U-3/4% Ti, and uranium alloys 3/4% Quad, 1% Quad, and 1% Quint have been studied utilizing a linear elastic fracture mechanics approach. The threshold stress intensities for stress corrosion crack propagation for these alloys have been determined in distilled H2O and NaCl solutions containing 50 ppm Cl− and 21,000 ppm Cl−. All of the alloys studied may be classified as very susceptible to SCC in aqueous solutions since they exhibit SCC in distilled H2O (<1 ppm Cl−) and have low KIscc values in NaCl solutions. Crack extension in all of the alloys in all environments was transgranular and failure occurred by brittle quasicleavage fracture in NaCl solution.

Effect of Ripple Load on Stress-Corrosion Cracking in Structural Steels

1991 ◽  
Vol 113 (1) ◽  
pp. 125-129 ◽  
Author(s):  
P. S. Pao ◽  
R. A. Bayles ◽  
G. R. Yoder
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Threshold Stress ◽  
Laboratory Data ◽  
Structural Steels ◽  
Corrosion Cracking ◽  
Critical Conditions ◽  
Time To Failure ◽  
Threshold Stress Intensity ◽  
Loading Effects

The presence of small ripple loading can, under certain circumstances, significantly reduce time-to-failure and threshold stress intensity for stress-corrosion cracking (SCC) of steels. A predictive framework for such ripple-loading effects (RLE) is developed from concepts and descriptors used in SCC and corrosion fatigue characterization. The proposed framework is capable of defining critical conditions required for the occurrence of RLE and predicting the time-to-failure curves. The agreement between the predicted and laboratory data is excellent.

scholarly journals Effect of Heat Treatment on Mechanical Properties and Susceptibility to Stress Corrosion Cracking of Aluminium Alloy

2013 ◽  
Vol 845 ◽  
pp. 178-182 ◽  
Author(s):  
Zahari Nur Ismarrubie ◽  
K.W. Loh ◽  
Hanafiah Yussof
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminium Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Tension Stress ◽  
Nacl Solution ◽  
Direct Tension ◽  
Retrogression And Reaging

The effect of the retrogression and reaging (RRA) heat treatment on the correlation between microstructure, mechanical properties and susceptibility to stress corrosion cracking (SCC) of the 6061-T6 aluminium alloy in dry air and sprayed in 3.5% NaCl solution has been studied. The as-received T6 alloy was subjected to retrogression at temperature 200°C for 10 minutes, quenching for 30 seconds and reaging at temperature 180°C for 24 h. In this study, the effect of RRA on mechanical properties of the as-received 6061-T6 alloy was investigated by tensile test in air and sprayed in 3.5% NaCl solution. Alternate immersion preparation was conducted to expose the as-received 6061-T6 alloys and RRA heat treated alloys into the corrosive environment, 3.5% NaCl solution for 20 days. The susceptibility to SCC was investigated by direct tension stress-corrosion (DTSC) tests sprayed in a 3.5% NaCl solution at crosshead speed of 0.2 mm/min; the loss of elongation (ELloss) was taken into account for the susceptibility to SCC. Generally, the RRA heat treatment improves the mechanical properties including yield strength, ultimate tensile strength and ductility. On the other hand, the RRA heat treatment decreases the susceptibility to SCC.

A Study on the Corrosion Behaviour of Aluminium Alloy 2014 T-651 Friction Stir Welds Using Stress Corrosion Cracking

2015 ◽  
Author(s):  
Thamilarasan Kollapuri ◽  
Madhanagopal Manoharan ◽  
Rajendra Boopathy Sadayan ◽  
Rama Koteswara Rao Sajja
Keyword(s):  
Aluminium Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Behaviour ◽  
Fracture Morphology ◽  
Corrosion Cracking ◽  
Al Alloy ◽  
Time To Failure ◽  
Friction Stir ◽  
Heat Treated

Stress Corrosion Cracking (SCC) is the initiation and slow growth of cracks under the influence of tensile stresses and aggressive corrosion environment. Al alloy 2014 T 651 was solution heat treated and stress-relieved. In the present work, Stress Corrosion Cracking (SCC) experimental arrangement has been used to test the severity of aluminium alloys under particular environmental conditions. Sound welds were obtained with Friction Stir Welding at rotational speed of 800 rpm and welding speed of 200 mm/min. Friction Stir Welds were cut into standard tensile specimens as per ASTM E8 standards. Time to failure of the welds were obtained using 3.5 wt% NaCl solution at pH 10 in 0.7 and 1.1 yields by Stress Corrosion Cracking. Vickers micro-hardness was taken along various regions of the weld. Optical micro-graphs and scanning electron fractographs were taken to analyse the fracture behavior and fracture morphology of Friction Stir Welded aluminium alloy specimens, subjected to Stress Corrosion Cracking.

Stress Corrosion Cracking of a New Rare- Earth Containing Magnesium Alloy, Elektron21 Compared with AZ91E

2011 ◽  
Vol 690 ◽  
pp. 361-364 ◽  
Author(s):  
Bharat S. Padekar ◽  
V.S. Raja ◽  
R.K. Singh Raman ◽  
Lyon Paul
Keyword(s):  
Rare Earth ◽  
Magnesium Alloy ◽  
Stress Corrosion ◽  
Yield Stress ◽  
Stress Corrosion Cracking ◽  
Constant Load ◽  
Corrosion Cracking ◽  
Load Test ◽  
Nacl Solution ◽  
Free Magnesium

Stress corrosion cracking (SCC) of a rare-earth (RE) containing and Al-free magnesium alloy, Elektron21 was studied using constant load test (CLT) in 0.1N NaCl solution saturated with Mg(OH)2.For comparison a common Al-containing and RE-free alloy, AZ91E was investigated. In CLT the threshold stress for SCC (σscc) for AZ91E was found to be 60% of the yield stress, whereas Elektron21 showed immunity to SCC even at stresses in the proximity of yield stress. The susceptibility of AZ91E to SCC and immunity of Elektron21 during CLT have been confirmed by fractography.

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