Showing papers on "Stress corrosion cracking published in 2020"
TL;DR: In this paper, a series of high-strength steels microalloyed with Nb and Sb were prepared via vacuum melting and hot rolling, and their resistance to stress corrosion cracking (SCC) was investigated through various tests in a SO2-polluted marine atmosphere.
65 citations
TL;DR: In this paper, the authors investigated the corrosion evolution and stress corrosion cracking behavior of E690 steel for marine equipment and construction under potentiostatic anodic polarization via electrochemical analysis, morphology and topography observation and slow strain rate tensile tests.
60 citations
TL;DR: In this article, the authors proposed a method to prevent penetration of lithium dendrites through solid electrolytes (SEs) by putting the SE surfaces into a state of residual compressive stress, such that cracks have difficulty forming, and cracks that do form are forced to close.
56 citations
TL;DR: In this paper, a new four-stage aging treatment by employing a natural aging prior to re-aging is designed to promote GP zones formation and subsequent shear-able strengthening effect in an Al-Zn-Mg-Cu alloy.
52 citations
TL;DR: In this paper, the effect of high hydrostatic pressure on stress corrosion cracking (SCC) of Ti-6Al-4V alloy in 3.5% NaCl solution at 2.5°C, by slow strain rate testing at 0.1
44 citations
TL;DR: In this article, stress corrosion cracking (SCC) behavior of a multiuse high-strength low-alloy (HSLA) bainite steel was comparatively studied in the simulated seawater and marine atmosphere environments using electrochemical measurements, static load SCC and slow strain rate tensile (SSRT) tests.
41 citations
TL;DR: A detailed analysis of machinability and stress corrosion cracking resistance (SCC) of SDSS under different coolant environments (Dry, Flood, Minimum quantity lubrication) is presented in this paper.
41 citations
TL;DR: In this paper, the environmental degradation of four different types of grain boundaries were investigated on alloy 690 following slow strain rate tensile tests in 360°C hydrogenated water, and it was shown that the grain boundary structure dependence of SCC resistance should be understood from its effects on solute diffusivity, structure of intergranular oxide and the local stress-strain state.
41 citations
TL;DR: The improved corrosion resistance of the samples subjected to 1 pass of ECAP compared to the samples in the as received condition and to the sample subjected to 2 and 4 passes represents the reason of their reduced SCC susceptibility.
Abstract: Despite the great potential of Mg and its alloys as material for biodegradable implants, their low resistance to the simultaneous action of corrosion and mechanical stresses in the human body have hampered their use. Stress Corrosion Cracking has been reported as one of the most critical failure modes to overcome to allow such materials to be clinically applied. Thus, in this paper we investigate the effect of Equal Channel Angular Pressing (ECAP) on the Stress Corrosion Cracking (SCC) susceptibility of the AZ31 Mg alloy. To do so, AZ31 alloy has been subjected to 1, 2 and 4 passes of ECAP, and the samples so obtained have then been tested by means Slow Strain Rate Tests (SSRTs) in Simulated Body Fluid (SBF) at 37 °C. Samples subjected to one pass of ECAP are shown to be less susceptible to SCC compared to the material in the as-received condition, while further ECAP processing (2 and 4 passes) are found to worsen the SCC susceptibility. To understand the different SCC susceptibilities shown by the differently ECAPed samples, microstructural analyses, potentiodynamic polarization curves, hydrogen evolution experiments and Scanning Electron Microscopy (SEM) analyses of the fracture surfaces were carried out. The improved corrosion resistance of the samples subjected to 1 pass of ECAP compared to the samples in the as received condition (due to a finer grain size) and to the samples subjected to 2 and 4 passes (due to a more favourable texture evolution) represents the reason of their reduced SCC susceptibility.
38 citations
TL;DR: In this article, the effect of different microstructural parameters on each failure mode was accurately investigated, and some techniques for improving the resistance of pipeline steels against these failure modes were suggested.
35 citations
07 Apr 2020-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, a recently developed 7A99 Al alloy was subjected to hot extrusion, solid solution and artificial aging, and their effects on mechanical properties and stress corrosion cracking were analyzed.
Abstract: A recently developed 7A99 Al alloy was subjected to hot extrusion, solid solution and artificial aging. The microstructure evolution and precipitation behavior were examined, and their effects on mechanical properties and stress corrosion cracking were analyzed. The results showed that the coarse Mg(Zn, Cu)2 phases were broken and refined by hot extrusion. Most of the phases dissolved into Al matrix during solution, and only insoluble Al7Cu2Fe phase was remained. GPI zones and η′ appeared in the under-aged and peak-aged samples. With the extension of aging time, stable η phase with large size formed and became the dominant precipitate in the over-aged sample. It was concluded that the precipitation of 7A99 Al during aging at 150 °C followed the sequence of solid solution → GPI zones → metastable η′ → stable η. The peak-aged sample owned the high yield and ultimate tensile strength of 588 MPa and 622 MPa, and a low elongation of 10.2%. The under-aged and over-aged samples exhibited relatively lower strength and higher elongations. 2% pre-stretching prior to aging could further improve the tensile properties. Both the under-aged and peak-aged samples were susceptible to the stress corrosion cracking, and the intergranular cracking was observed. In contrary, the over-aged sample showed much better corrosion resistance with a typical ductile fracture, due to the coarsening and separation of grain boundary precipitations.
TL;DR: In this paper, the corrosion and stress corrosion cracking behavior of carbon steel at medium hydrofluoric acid concentration was investigated, and pits were found as a consequence of hydrogen escaping and uneven distribution of corrosion products, and the higher the stress, the shorter the pit-to-crack transition time and the change in crack propagation rate with stress.
TL;DR: The improved corrosion resistance due to the increased extension of the nano-surface layer and to the compressive residual stresses represents the reason of the reduced SCC susceptibility of cryogenically machined AZ31 samples as compared to dry machined ones.
Abstract: Magnesium and its alloys have recently attracted great attention as potential materials for the manufacture of biodegradable implants. Unfortunately, their inadequate resistance to the simultaneous action of corrosion and mechanical stresses in the human body have hampered their use as implant materials. This work aims at evaluating the Stress Corrosion Cracking (SCC) susceptibility of the AZ31 Mg alloy after being machined under cryogenic cooling. The SCC behaviour was evaluated by means of Slow Strain Rate Tests (SSRTs) in Simulated Body Fluid (SBF) at 37 °C. Prior to testing, a full characterization of the machined surface integrity, including microstructural observations, residual stress, nano-hardness measurements and surface texture analysis was carried out together with the assessment of the corrosion properties through potentiodynamic polarization curves. In addition, the morphology of the fracture surfaces after SSRTs was analysed by means of 3D optical profiler and Scanning Electron Microscopy (SEM). The improved corrosion resistance due to the increased extension of the nano-surface layer and to the compressive residual stresses represents the reason of the reduced SCC susceptibility of cryogenically machined AZ31 samples as compared to dry machined ones.
TL;DR: In this article, the fatigue behavior of the extruded Mg-Zn-Y-Nd alloy used for vascular stents was studied both in air and in simulated body fluid (SBF).
TL;DR: In this article, the fine precipitate dispersion in the grain interiors is similar in the peak aged and RRA tempers, and upon RRA, precipitates inside the grains are enriched in Cu, lowering the Cu matrix content, and reducing the relative difference in the Cu precipitate composition between bulk and grain boundaries.
TL;DR: In this paper, the authors studied the SCC mechanism of AISI 316 LN rebar along the entire stress-strain diagram by slow strain rate technique and proved that the growth and passivity breakdown of the passive film is proved by non-destructive electrochemical tests as well as by current monitoring.
TL;DR: In this article, the feasibility of using a non-contact high-resolution microwave sensor for the detection and mitigation of High pH Stress Corrosion Cracking (HpHSCC) through monitoring the pH range beneath the dsibonded coating in buried pipeline steel has been investigated.
Abstract: Here, the feasibility of using a non-contact high-resolution microwave sensor for the detection and mitigation of High pH Stress Corrosion Cracking (HpHSCC) through monitoring the pH range beneath the dsibonded coating in buried pipeline steel has been investigated. A modelling method and microwave dielectric sensing for aqueous solution has been studied in order to relate relative permittivity and loss to the pH level using the concentration as a bridge. The experimental results showed the potential of the high quality-factor sensor for monitoring the pH level variation. The resonant frequency of the microwave sensor was the main variable considered in the characterization of the sensor’s response to pH level changes or concentration variations in the defect beneath the pipe coating. Additionally, the extracted experimental results for near-neutral and acidic pH environment detection demonstrated the significance of non-contact sensing performance and the sensor’s potential to detect and study the pH variation. The results demonstrate significantly distinct frequency shift of 174 kHz as the pH increases from 7 to 11 which is the range of the pH created in HpHSCC. This method, as an example, could be employed in the third stage of Stress Corrosion Cracking Direct Assessment (SSCDA), Direct examination step, to determine whether breeding ground for HpHSCC is created or not.
TL;DR: In this paper, 5083 aluminum alloy sheets with different recrystallized textures (a low-intensity texture, a cube-based texture, and a brass-based one) were obtained by cold rolling and annealing.
TL;DR: A feasibility study of the cold spray deposition process of 304L stainless steel on 304 stainless steel substrates as a mitigation method for chloride-induced stress corrosion cracking (CISCC) has been investigated under various substrate conditions as discussed by the authors.
TL;DR: The impacts of SO2 on corrosion and stress corrosion cracking (SCC) of supercritical CO2 pipeline steels are unclear because of limited field operation experience and somewhat controversial reported results as discussed by the authors.
TL;DR: In this article, a detailed SCC mechanism was studied by advanced detection methods, and cracks propagated along the interface with low residual strain at various cathodic potentials, indicating that the low residual path is more active for both the anodic reaction and dislocation emission, and the high residual strain area may act as the cathodic zone.
TL;DR: In this article, the authors investigated the SCC mechanism of rusted X100 steel in a wet-dry cycle environment at various Cl− and HSO3− contents, and concluded that SCC cracking is initiated at pits formed by anodic dissolution, while the hydrogen-evolution mechanism dominates in a high HSO 3− concentration environment.
TL;DR: In this article, a simulated polluted marine atmosphere was used to study the corrosion and stress corrosion cracking behavior of some low-alloy high-strength steels microalloyed with Nb and Sb.
Abstract: Corrosion and stress corrosion cracking (SCC) behavior of some low-alloy high-strength steels microalloyed with Nb and Sb were in detail studied in a simulated polluted marine atmosphere. The results indicated that the high-strength steel without Nb and Sb was badly damaged by corrosion and very susceptive to SCC in a SO2-containing marine atmosphere, which was characterized by high corrosion rate and a large number of potential initiation sites for SCC cracks. By contrast, Nb addition affected little on atmospheric corrosion rate, but weakened the role of hydrogen at the boundaries of prior austenite grain and lath bainite. Sb addition significantly reduced the corrosion rate by optimizing the properties of rust layer through its synergy with Cu, and inhibited the localized anodic dissolution and acidification effect underneath. Thus, the combined addition of Nb and Sb increased the resistance to atmospheric corrosion and substantially inhibited SCC initiation.
TL;DR: In this article, the evolution of electrochemical behavior of API X70 pipeline steel during active dissolution in 1M NaHCO3 was investigated by electrochemical impedance spectroscopy (EIS), which revealed that the metal dissolution rate is limited by slow inward diffusion of CO3−2 ions through a porous precipitated corrosion product layer to the steel surface.
23 Dec 2020
TL;DR: The main topic of this review is centered on the approaches that can be used in elaborating AE data to better discriminate the mechanisms that contribute to damage propagation in SCC conditions.
Abstract: The complex nature of the damage evolution in stress corrosion cracking (SCC) leads to explore for new investigation technologies in order to better identify the mechanisms that supervise the initiation and evolution of the damage as well to provide an improvement of knowledge on this critical localized corrosion form during time. Research activities concerning the use of acoustic emission (AE) technique to assess SCC has acquiring considerably relevance in recent decades. The non-invasiveness and the possibility to provide a continuous in situ monitoring of structures and components make this non-destructive technique clearly promising in the field of structural health monitoring. In this concern, this paper aims to be a focused overview on the evaluation of SCC phenomena by AE technique. The main topic of this review is centered on the approaches that can be used in elaborating AE data to better discriminate the mechanisms that contribute to damage propagation in SCC conditions. Based on available literature, investigation approaches assessing AE waveform parameters were classified, evidencing, furthermore, the identified mechanisms that synergistically take place during the material degradation. Eventually, a brief summary and a future trend evaluation was also reported.
TL;DR: This straightforward conformal surface treatment can be useful as a workaround for one of the major bottlenecks of biomedical Mg based implants and hence provides a possible pathway for making them more commonplace in the field.
Abstract: Magnesium and its alloys have been widely studied as materials for temporary implant devices. However, corrosion-assisted cracking phenomena such as stress corrosion cracking (SCC) continue to prevent their mainstream use. For the first time, we explore the SCC susceptibility of Atomic Layer Deposition (ALD) coated AZ31 alloys in Simulated Body Fluid (SBF). Conformal 100 nm coatings of titania and zirconia were deposited on standard dogbone specimens and subjected to slow strain rate tests at 3.5 10-6 s-1 and a temperature of 37 °C. Remarkably, the SCC susceptibility index IUTS was reduced by 6% and 40% and the Ie was reduced by more than 70% and 76% with a titania and zirconia coating, respectively. Potentiodynamic polarization, hydrogen evolution and fracture behavior of the samples revealed the drastic corrosion reduction to be the main reason for the susceptibility reduction. We discuss the observed SCC behavior of our samples in light of the coatings’ electrochemical activities, wettabilities, surface integrities and mechanical properties. This straightforward conformal surface treatment can be useful as a workaround for one of the major bottlenecks of biomedical Mg based implants and hence provides a possible pathway for making them more commonplace in the field.
TL;DR: In this paper, the stress corrosion cracking behavior of X100 steel under alternating dry/wet conditions was investigated through electrochemical experiments and slow strain-rate testing, and the results showed that the corrosion morphology transforms from general corrosion to pitting with increasing dry-wet ratio (D/W).
TL;DR: In this paper, the authors showed that SCC initiated along the grain boundaries that exhibited diffusion-induced grain boundary migration (DIGM), as well as enrichments in Al and Ti.
TL;DR: In this article, the SCC susceptibility of the base and weld metals of the dissimilar metal weld joint following the order of SA508 was investigated by the interrupted slow strain rate tension tests following a microstructure characterization.
TL;DR: In this article, the effects of titanium ion implantation on the stress corrosion cracking (SCC) behavior of 304 austenitic stainless steel were studied, and slow strain rate tests were conducted on 304 steel.
Abstract: The effects of titanium ion implantation on the stress corrosion cracking (SCC) behaviour of 304 austenitic stainless steel were studied. Slow strain rate tests (SSRTs) were conducted on 304 steel ...