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.

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.

scholarly journals THE INFLUENCE OF MICROSTRUCTURAL FACTORS AND HEAT TREATMENT ON THE CORROSION RESISTANCE OF REINFORCING STEEL CLASS A 600

2018 ◽  
Vol 22 (2) ◽  
pp. 52-63 ◽  
Author(s):  
N. N. Sergeev ◽  
V. V. Izvol'skiy ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Chemical Composition ◽  
Carbon Content ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Steel Reinforcement ◽  
Reinforcing Steel

Currently, hot rolled bar reinforcement class A600 of low-alloy steels in the delivery condition has a high tendency to this very specific kind of destruction as stress corrosion cracking under tension (SCC). However, there are cases of collapse of pre-stressed concrete structures, in most cases initiated corrosion cracking under stress, put the problem this type of fracture is particularly acute. In stress corrosion cracking cracks occur, the occurrence of which depends not only on the structural state of the material, the type and level of stress, but also on the degree of aggressiveness of the environment in which the operation occurs. In this regard, it is very important to establish how the corrosion resistance of class A600 reinforcing steel varies depending on the change in the chemical composition, microstructure, the level of applied and residual micro-stresses, and various modes of heat treatment. The purpose of this paper is to study the effect of the above factors on the resistance of low-alloyed reinforcing steel class A600 stress corrosion cracking It is shown that the sensitivity of the reinforcement to stress corrosion cracking is largely determined by the chemical composition (mainly carbon content), the type of microstructure and the level of residual micro-stresses. The influence of heat treatment regimes on the corrosion resistance of A600-grade reinforcing steel in nitrates solutions is investigated. It is shown that the use of additional heat treatment (normalization and improvement) increases the corrosion resistance of steel. High corrosion resistance steel reinforcement has only a carbon content at the lower limit of the vintage composition, which is provided by the structure of homogeneous bainite with mechanical properties at the level of strength class A600. With higher mechanical properties, the steel reinforcement has lower corrosion resistance.

Effects of pH Value on the Stress Corrosion Cracking of Super 13Cr Tubing Steel

2012 ◽  
Vol 557-559 ◽  
pp. 127-130 ◽  
Author(s):  
Xiao Fei Yao ◽  
Fa Qin Xie ◽  
Xiang Qing Wu ◽  
Yi Fei Wang
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Acidic Medium ◽  
Ph Value ◽  
Fracture Morphology ◽  
Corrosion Cracking ◽  
Nacl Solution ◽  
Susceptibility Index ◽  
Experiment Method ◽  
Effects Of Ph

Effects of pH value on the stress corrosion cracking (SCC) of super 13Cr tubing steel were investigated in 3.5% NaCl solution, that mechanics properties and fracture morphology and SCC resistance and stress corrosion cracking susceptibility index (kscc) were analyzed by slow strain rate tensile (SSRT) stress corrosion cracking experiment method and σ-ε curve and SEM. the results Effects of pH value on the stress corrosion cracking (SCC) of super 13Cr tubing steel were investigated in 3.5% NaCl solution, that mechanics properties and fracture morphology and SCC resistance and stress corrosion cracking susceptibility index (kscc) were analyzed by slow strain rate tensile (SSRT) stress corrosion cracking experiment method and σ-ε curve and SEM. the results showed that super 13Cr tubing steel has good properties of resistance stress corrosion cracking in acidic medium, effects of pH value on super13Cr tubing steel resistance stress corrosion was not very obviously in the acidic medium, with pH value decreased, super 13Cr tubing steel tensile strength decreased, elongation rate decreased, fracture area contraction ratio decreased, break time reduced, the tendency of the stress corrosion cracking increased. the stress corrosion cracking susceptibility index kσ and kε were all increasing, that increased degree of kε were obviously than kσ, effects of pH value on the plastic deformation of super 13Cr tubing steel were greater than tensile strength.

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