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Showing papers on "Stress corrosion cracking published in 2011"


Journal ArticleDOI
TL;DR: In this paper, an overview of the aspects which determine the corrosion of Mg alloys: measurement details; impurity elements Fe, Ni, Cu and Co; second phases; surface films and surface condition and (v) stress corrosion cracking (SCC).
Abstract: Much of our understanding of the Mg corrosion mechanism is based on research using aggressive chloride based solutions like 3% NaCl, which are appropriate for understand the corrosion for applications such as auto construction. The chloride ions tend to cause break down of the partly protective surface film on the Mg alloy surface. The corrosion rate increases with exposure time until steady state is reached, which may take several weeks. An overview is provided of the aspects which determine the corrosion of Mg alloys: (i) measurement details; (ii) impurity elements Fe, Ni, Cu and Co; (iii) second phases; (iv) surface films and surface condition and (v) stress corrosion cracking (SCC). This understanding is used to help understand Mg corrosion for Mg as a biodegradable implant for medical applications. Solutions that elucidate these applications tend to form surface films and the corrosion rate tends to decrease with immersion time.

357 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of surface preparation method on the susceptibility of a 304H stainless steel to stress corrosion cracking under simulated atmospheric corrosion conditions was investigated, where MgCl2 was deposited onto four-point bend specimens, which were then placed in a chamber with a relative humidity of 45% and temperature of 60 °C.

180 citations


Journal ArticleDOI
TL;DR: In this paper, pure iron and a ferrite-bainite steel were charged electrochemically using various electrolytes and combinations of current density and charging time to identify the experimental conditions where blister formation occurred.

162 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of retrogression and re-aging treatment on the microstructure, strength, exfoliation corrosion, intergranular corrosion and stress corrosion cracking of an Al-Zn-Mg-Cu alloy has been investigated by means of optical microscope (OM), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS).

160 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of residual stress generated during tube fabrication, roll expansion and machining of stainless steel on the stress corrosion cracking (SCC) susceptibility was studied by testing fabricated tubes, tube-tube sheet joint and heavily machined plate of austenitic stainless steel (SS) in boiling MgCl2.

141 citations



Journal ArticleDOI
TL;DR: In this article, the most current uses of aluminium alloys are first summarised, and their different corrosion modes, i.e. pitting, crevice, filiform, galvanic and structural corrosion (including intergranular, exfoliation and stress corrosion cracking) are reviewed, with particular attention paid to metallurgical factors controlling the corrosion process.
Abstract: Aluminium is the second most often used metal after steel. In this paper, the most current uses of aluminium alloys are first summarised. Then, their different corrosion modes, i.e. pitting, crevice, filiform, galvanic and structural corrosion (including inter-granular, exfoliation and stress corrosion cracking) are reviewed, with particular attention paid to metallurgical factors controlling the corrosion process. For each mode, some instances of possible in-service failure are given, followed by the discussion of the involved mechanisms and the presentation of appropriate solutions to prevent corrosion. Last, passivity and polarisation behaviour are discussed with reference to stainless steels.

117 citations


Journal ArticleDOI
TL;DR: In this article, the effect of repetitious-retrogression and reaging (repetitious-RRA) treatment on the strength and SCC resistance of Al-Zn-Mg-Cu alloy was investigated by the slow strain rate technique (SSRT) and electrical conductivity test, using TEM, EDS and SEM.
Abstract: Influence of repetitious-retrogression and reaging (repetitious-RRA) treatment on the strength and SCC resistance of Al–Zn–Mg–Cu alloy was investigated by the slow strain rate technique (SSRT) and electrical conductivity test, using TEM, EDS and SEM. Additionally, the strength of alloy was characterized by Vickers hardness. The results show that within 3 times RRA treatments, SCC resistance increases with the increase of time, while maintaining strength as compared to RRA treatment, TEM observation along with EDS analysis indicates that within 3 times, matrix precipitates (MPs) in repetitious-RRA treatment are similar to those by RRA treatment and grain boundary precipitates (GBPs) become more discrete and coarser with the time. However, RRA treatment reaches 4 times, the SCC resistance gets worse because MPs are also coarse. Besides, the Cu content of GBPs increases with the time, inversely for Zn content, which is another reason for improving the SCC resistance.

113 citations


Journal ArticleDOI
TL;DR: In this paper, failure mechanisms were determined based on available documents and metallographic studies conducted on a high-pressure gas pipeline steel in northern regions of Iran, after almost 40 years since its installation.

103 citations


Journal ArticleDOI
TL;DR: In this article, the fine scale microstructure of Al-5083 (H-131) sensitized at 448 K (175 °C) for 1, 10, 25, 50, 100, 240, 500, and 1000 hours has been investigated using transmission electron microscopy (TEM) to study the evolution of the β phase (Al3Mg2) at grain boundaries and on pre-existing intragranular particles.
Abstract: The fine scale microstructure of Al-5083 (H-131) sensitized at 448 K (175 °C) for 1, 10, 25, 50, 100, 240, 500, and 1000 hours has been investigated using transmission electron microscopy (TEM) to study the evolution of the β phase (Al3Mg2) at grain boundaries and on pre-existing intragranular particles. In fully sensitized Al-5083, the β phase (Al3Mg2) forms heterogeneously both at grain boundaries and on pre-existing particles, which are enriched in manganese. TEM observations showed that the grain boundary precipitation of the β phase initially occurs between 0 to 1 hour of aging at 448 K (175 °C), and that the β phase grows with a ribbonlike morphology. The grain boundary planes are covered by the β phase after 240 hours of aging. The contribution of microstructure, defects, and environment on the stress corrosion cracking (SCC) behavior is discussed.

100 citations


Journal ArticleDOI
TL;DR: In this article, the influence of zinc on a ∑5(0.1/2) aluminum grain boundary was investigated by means of first principles calculations with the full potential linearized augmented plane wave method using two approaches: (i) within the framework of the Rice-Wang thermodynamic model; (ii) by the ab initio tensile test method.

Journal ArticleDOI
Gang Du1, Jie Li1, Wenhang Wang1, C. Jiang1, Shizhe Song1 
TL;DR: In this article, the authors focused on the corrosion process of 304 stainless steel in acidic NaCl solution during slow strain rate testing experiment by using electrochemical noise (EN) and acoustic emission (AE) techniques.

Journal ArticleDOI
TL;DR: In this paper, the effects of key parameters such as material composition, irradiation dose, and water chemistry on IASCC susceptibility and crack growth rates of Austenitic stainless steels in light water reactor (LWR) environments were evaluated.

Journal ArticleDOI
TL;DR: In this paper, the growth rate of stress corrosion cracking (SCC) was measured for cold-worked, thermally treated Alloy 690 (UNS N06690, CW TT 690) and cold-work, solution-treated Alloy690 (CW ST 690), in hydrogenated pressurized water reactor (PWR) primary water under static load condition.
Abstract: The growth rate of stress corrosion cracking (SCC) was measured for cold-worked, thermally treated Alloy 690 (UNS N06690, CW TT 690) and cold-worked, solution-treated Alloy 690 (CW ST 690) in hydrogenated pressurized water reactor (PWR) primary water under static load condition. Three important patterns were observed. First, intergranular stress corrosion cracking (IGSCC) was observed in CW TT 690 in PWR primary water in the range between 320°C and 360°C; this rate of SCC growth was slower than in CW mill-annealed Alloy 600 (UNS N06600, CW MA 600). No significant IGSCC was observed in CW ST 690 after 5,109 h in hydrogenated PWR primary water at 360°C. This is opposite of the behavior reported in the literature for high-temperature caustic solutions. Second, to assess the role of creep, rates of creep crack growth were measured in air, argon, and hydrogen gas environments using 20% CW TT 690 and 20% CW MA 600 in the range between 360°C and 460°C; intergranular creep cracking (IG creep cracking) wa...

Book ChapterDOI
01 Jan 2011
TL;DR: In this article, basic aspects of stress-corrosion cracking (SCC) in metallic materials are outlined, followed by a summary of the numerous mechanisms that have been proposed for SCC.
Abstract: Basic aspects of stress-corrosion cracking (SCC) in metallic materials are outlined, followed by a summary of the numerous mechanisms that have been proposed for SCC. The characteristics of transgranular and intergranular SCC in model systems, e.g. pure metal and single-phase alloy single crystals and bi-crystals under testing conditions that facilitate discrimination between mechanisms, are then described. The applicability of the various proposed mechanisms, such as those based on dissolution, hydrogen embrittlement, film-induced cleavage, and adsorption, are discussed in detail for these systems. Mechanisms of SCC in complex commercial alloys are then considered in the light of these studies on model systems.

Journal ArticleDOI
TL;DR: In this paper, the effect of irradiation is to enhance an inherent susceptibility to stress corrosion cracking (SCC), which results from a confluence of stress, microstructure, and water chemistry, and each is affected by irradiation.
Abstract: Irradiation-assisted stress corrosion cracking (IASCC) is aptly named since the effect of irradiation is to enhance an inherent susceptibility to stress corrosion cracking (SCC). This chapter introduces the basic SCC dependencies in austenitic stainless steels and nickel alloys under unirradiated conditions and then describes how they are accentuated or diminished as a result of radiation. SCC results from a confluence of stress, microstructure, and water chemistry, and each is affected by irradiation. With increasing plant operation and improved laboratory capability, it has been concluded that true immunity to SCC growth apparently does not exist in common engineering materials although different conditions can produce large changes in SCC susceptibility. As nuclear power plants operate longer, an increased incidence of SCC can be expected unless active mitigation steps are taken.

Journal ArticleDOI
TL;DR: In this article, the authors found that grain boundary cracking susceptibility was associated with slip continuity, indicating that the strain accommodation at the boundary is related to cracking resistance, and higher susceptibility was also found at grain boundaries adjacent to grains with low Schmid factor or high Taylor factor.
Abstract: Irradiation assisted stress corrosion cracking may be linked to the local slip behavior near grain boundaries that exhibit high susceptibility to cracking. Fe–13Cr–15Ni austenitic steel was irradiated with 2 MeV protons at 360 °C to 5 dpa and strained in 288 °C simulated BWR conditions. Clusters of grains from the experiment were created in an atomistic simulation and then virtually strained using molecular dynamic simulation techniques. Cracking and grain orientation data were characterized in both the experiment and the simulation. Random high angle boundaries with high surface trace angles with respect to the tensile direction were found to be the most susceptible to cracking. Grain boundary cracking susceptibility was also found to correlate strongly with slip continuity, indicating that the strain accommodation at the boundary is related to cracking resistance. Higher cracking susceptibility was also found at grain boundaries adjacent to grains with low Schmid factor or high Taylor factor. The basic trends reported here are supported by both the experiments and the simulations.

Journal ArticleDOI
TL;DR: In this article, electron-back scattering diffraction and hardness measurements were used to measure the microstructure and local deformation in 316NG weld heat-affected zones, where intergranular cracking along random boundaries was observed near the weld fusion line.

Journal ArticleDOI
TL;DR: In this paper, a method of introduction of compressive residual stress using cavitation impacts was proposed, without use of shots, in order to eliminate stress corrosion cracking in stainless steel.
Abstract: In order to eliminate stress corrosion cracking, a method of introduction of compressive residual stress using cavitation impacts was proposed, without use of shots. The cavitation impacts were successfully produced by a cavitating jet in air, without the requirement of a water-filled chamber. The injection condition of the jet was optimized and the introduction of compressive residual stress into stainless steel was demonstrated using the jet. The maximum compressive residual stress introduced by the optimized jet was 500 MPa on the surface, while the thickness of the modified layer was up to 400 μm. A method for estimation of the introduced compressive residual stress by the jet as a function of processing time was proposed, considering the stochastic phenomena of the cavitation impacts. Both the intense impact at 0.2 Hz and relatively weak impact at 4.5 Hz affect the introduction of compressive residual stress. The value of the residual stress and the thickness of the modified layer can be estimated by the proposed experimental equation.

Journal ArticleDOI
TL;DR: In this article, the effect of dissolved hydrogen (DH) levels on the Ni/NiO phase transition was investigated by employing electrochemical and exposure experiments, and the results showed that increasing DH in water decreased the thickness and the ionic defect transport resistance of the oxide film, in conjunction with the increase of Cr- but decrease of Ni-concentrations in the oxide.

Journal ArticleDOI
TL;DR: In this article, an overview of Mg SCC is provided, and a detailed study of H-trap interactions is needed in order to design alloys resistant to TGSCC.
Abstract: An overview is provided of Mg SCC. Intergranular stress corrosion cracking (IGSCC) is typically caused by a continuous second phase along grain boundaries. The second phase causes microgalvanic corrosion of the adjacent Mg matrix. IGSCC is expected for all creep resistant Mg alloys in contact with water whenever creep resistance is produced by a continuous second phase along the grain boundaries. IGSCC can be avoided by appropriate Mg alloy design. Transganular SCC (TGSCC) is caused by an interaction of hydrogen (H) with the microstructure so a detailed study of H-trap interactions is needed in order to design alloys resistant to TGSCC. This understanding is urgently needed because Mg alloys are being increasingly used in load bearing applications; many common Mg alloys have a threshold stress for SCC of half the yield stress in common environments including high-purity water.

Journal ArticleDOI
TL;DR: In this paper, the grain boundary microstructure, strain distribution and stress corrosion cracking (SCC) in one dimensional (1D), two dimensional (2D) and three dimensional (3D) cold worked Alloy 600 were investigated.

Journal ArticleDOI
TL;DR: In this paper, the role of CO 2 and cyclic stress R -ratio (R ǫ = minimum stress/maximum stress) on near neutral pH SCC initiation mechanism(s) under a disbonded coating of pipeline steel protected by cathodic protection (CP).

Journal ArticleDOI
TL;DR: In this article, micro-electrochemical techniques, including localized electrochemical impedance spectroscopy and scanning vibrating electrode technique, were used to characterize quantitatively the synergistic effects of hydrogen and stress on local dissolution at crack-tip of a X70 pipeline steel in a near-neutral pH solution.

Journal ArticleDOI
Zhanpeng Lu1, Tetsuo Shoji1, Fanjiang Meng1, Yubing Qiu1, Tichun Dan1, He Xue1 
TL;DR: In this article, the effects of electrode potential, stress intensity factor and loading history on stress corrosion cracking growth of a cold-rolled 316NG stainless steel in 288°C pure water were investigated.

Journal ArticleDOI
TL;DR: In this article, the weld metal in multi-pass Alloy 52-A508 dissimilar welds was examined and an approximately 2mm wide transition zone was observed that consisted of a martensitic layer (10 20 um) along the weld interface and the austenite phase region with varying degrees of dilution.
Abstract: In the nuclear power industry, dissimilar metal welding is widely used for joining low alloy steel to austenite stainless steel components with nickel-base filler metals. In this study, attention was paid to the weld metal in multi-pass Alloy 52-A508 dissimilar welds. An approximately 2mm wide transition zone was observed that consisted of a martensitic layer (10 20 um) along the weld interface and the austenite phase region with varying degrees of dilution. After post-weld heat treatment, the microstructures near the weld interface consisted of martensite, carbides and Type II boundaries. The presence of Type II boundaries significantly reduced the resistance to stress corrosion cracking (SCC) and formed intergranular cracking under simulated reactor coolant conditions. Constant extension rate tensile (CERT) tests were performed on the notched tensile specimens in 300 C water at two extension rates, 3 10 4 and 1 10 6 mm/s. A fast CERT test can be regarded to have no contribution of corrosion, and its results can be used as standards for comparison. In the slow CERT tests, the ductility losses of round-bar specimens with a circumferential notch at various regions in the weld metal were ranked accordingly. The relative susceptibility to SCC in terms of the ductility loss in increasing order of severity was as follows: the undiluted weld metal, the transition zone and the weld interface. SEM fractographic observations were consistent with the SCC results, i.e., an increased ductility loss or SCC susceptibility was associated with more brittle fractures. [doi:10.2320/matertrans.M2010294]

Journal ArticleDOI
TL;DR: In this paper, the role of microstructure and water chemistry in stress corrosion cracking in Alloy 182-low alloy steel (LAS) dissimilar weld joint in 288°C water was investigated by experiments and finite element simulation.

Journal ArticleDOI
TL;DR: In this paper, stress corrosion cracking of as-quenched 4340 and 3.5NiCrMoV steels was studied under hydrogen charging conditions, with a cathodic current applied to the gauge length of specimens subjected to Linearly Increasing Stress Test (LIST) in 0.5M H 2 SO 4 solution containing 2.5g/l arsenic trioxide (As 2 O 3 ) at 30°C.

Journal ArticleDOI
TL;DR: In this paper, the authors conducted constant load tests in NS4 solution purged with N2-5% CO2 gas mixture on American Petroleum Institute (API) X80 pipeline steel applied in the 2nd West-East Gas Pipeline project with and without preload.

Journal ArticleDOI
TL;DR: In this article, the results of general corrosion and stress corrosion cracking (SCC) susceptibility tests in supercritical water (SCW), studied for austenitic stainless steel 316L, with the aim to identify maximum SCW temperature usability and specific failure mechanisms prevailing during slow strain-rate tensile (SSRT) tests in ultrapure demineralized SCW solution with controlled oxygen content.