Glutaraldehyde (GA) is widely employed as a biocide to control microbiologically influenced corrosion in oil fields and industrial water treatment. It might be corrosive to metal. In this study, the effect of glutaraldehyde on the corrosion behavior...
In this study, the Void Growth Model (VGM) is employed to predict the ductile fracture of X80 pipeline steel. The X80 pipeline tends to be applied in challenging scenarios, such as extremely deep water and long-distance pipelines, which might cause a...
The microstructure evolution and variation of impact toughness in the heat-affected zone (HAZ) of X80 pipeline steel with different Nb content under different peak temperatures in the secondary thermal cycle were studied through welding thermal simul...
X80 pipeline steel is a key material in the field of oil and gas transportation. Its damage behavior in a hydrogen-filled environment directly affects pipeline safety. In this study, through hydrogen permeation experiments and slow strain rate tensil...
In this study, the welding stress of in-service welding on the X80 steel pipeline was investigated using the 3D finite element method. The parameters of heat source and axial and hoop welding stress were verified in the experiment. As shown in the re...
A nondestructive evaluation of the hydrogen damage of materials in a hydrogen environment is important for monitoring the running conditions of various pieces of equipment. In this work, a new thermostatic electrolytic hydrogenation in situ ultrasoni...
The microstructure and corrosion resistance in H2S environments for various zones of X80 pipeline steel submerged arc welded joints were studied. The main microstructures in the base metal (BM), welded metal (WM), coarse-grained heat-affected zone (C...
The hydrogen concentration in steel is directly related to the hydrogen embrittlement (HE) sensitivity of the steel. This study combined electrochemical hydrogen charging, the slow strain rate test (SSRT), and hydrogen permeation experiments to inves...
AC corrosion has been considere d as a threat to the corrosion of buried pipelines. Effects of sulfate-reducing bacteria (SRB) and alternating current (AC) on corrosion of X80 pipeline steel in soil-extract solution were investigated by electrochemic...
X80 pipeline steel has played a vital role in oil and gas transportation in recent years. However, hydrogen-related issues frequently lead to pipeline failures during service, resulting in significant losses of properties and lives. Three heat treatm...
In this manuscript, the effects of Mo content on the microstructure and impact toughness of X80 thick-walled low-temperature pipeline steel were studied. Two test steels with different Mo content (0.25% and 0.40%) were prepared by the thermo-mechanic...
The residual stress significantly affects the operational safety of oil and gas pipelines. Traditional ultrasonic stress measurement methods require pipeline surface pretreatment, which reduces detection efficiency. EMAT, as a non-contact measurement...
In this study, an optimum tempering temperature after a thermo-mechanical control process (TMCP) was proposed to improve the hydrogen-induced ductility loss of high-vanadium X80 pipeline steel. The results showed that with increasing tempering temper...
This study systematically investigated the corrosion evolution and protective mechanisms of X80 pipeline steel in Xinjiang’s saline soil environments under freeze–thaw cycling conditions. Combining regional soil characterization with labo...
We studied the effects of peak temperature and cooling rate in the secondary welding thermal cycles on the martensite/austenite (M/A) constituents’ characteristics (including fraction, average size and distribution), corrosion resistance and hy...
X80 pipeline steel is widely used in oil and gas pipelines because of its excellent strength, toughness, and corrosion resistance. It is welded via gas metal arc welding (GMAW), risking high cold crack sensitivities. There is a certain relationship b...
The X90 pipeline steel with high-strength and high-toughness become the most popular pipeline steel. Due to the stress triaxial constraint and fracture toughness properties are the key factors for the stable work of pipeline steel, the research on th...
This study used a digital imaging technique (DIC) to obtain the strain distribution at various locations in undermatching X80 pipe girth-weld joints under uniaxial tensile loading. In addition, the microstructure characteristics and deformation patte...
Due to the limitations of the energy density and penetration ability of arc welding technology for long-distance pipelines, the deterioration of the microstructures in the coarse-grained heat-affected zone (HAZ) in welded joints in large-diameter, th...
High-energy beam welding was introduced for pipeline steel welding to reduce pipeline construction costs and improve the efficiency and safety of oil and gas transportation. Microstructures and their distribution in X100 laser-welded joints, which de...
Corrosive fatigue failure of submarine pipelines is very common because the pipeline is immersed in a sea environment. In Bohai sea, many old pipelines are made of API 5L X56 steel materials, and it is necessary to provide an accurate method for pred...
In this study, a non-stationary electrochemical model was verified to be equally applicable to X70 pipeline steel under polarization potential in a marine environment, and the mechanism of stress corrosion cracking (SCC) was revealed. A quick SCC eva...
The strengthening mechanism of X100 high steel grade pipeline steel, including grain boundary strengthening, solution strengthening, precipitation strengthening, dislocation strengthening, and texture strengthening, was analyzed by the technics of sc...
The existing studies mainly focus on the coarse-grained heat-affected zone and the inter-critically reheated coarse-grained heat-affected zone, while the studies on other sub-zones are relatively low. Meanwhile, the studies on the Cr element in steel...
The microstructure and mechanical properties of X70 pipeline steel with a ferrite/martensite dual-phase microstructure produced by thermo-mechanical controlled processing were investigated by tensile tests, Charpy V-notched (CVN) impact tests, drop-w...
In this paper, the microstructural and mechanical properties of a high-strength low-alloy (HSLA) API 5L X52 steel, which is widely utilized in the construction of gas pipelines, were characterized with optical microscopy, electron backscatter diffrac...
Strain-based design (SBD) plays an important role in pipeline design and assessment of pipelines subjected to geo-hazards. Under such hazards, a pipe can be subjected to substantial plastic strains, leading to tensile failure at locations of girth we...
In this paper, the effects of dispersed 3~10 nm NbC precipitates on hydrogen diffusion in X80 pipeline steel were investigated by means of high resolution transmission electron microscopy (HRTEM), electrochemical hydrogen permeation, and thermal deso...
The present research focuses on the investigation of an in situ hydrogen charging effect during Crack Tip Opening Displacement testing (CTOD) on the fracture toughness properties of X65 pipeline steel. This grade of steel belongs to the broader categ...
The hydrogen/deuterium permeation behavior of X52MS pipeline steel with three thicknesses was investigated using the gas/liquid phase permeation method by changing the current density and regulating the surface roughness. The permeation curves under...
The relationship between microstructure and tensile properties of an Nb–Ti microalloyed X90 pipeline steel was studied as a function of finish rolling temperature using a Gleeble 3500 simulator, an optical and scanning electron microscope, electron b...
The aim of this research was to investigate the influence of metallurgy on the corrosion behaviour of separate weld zone (WZ) and parent plate (PP) regions of X65 pipeline steel in a solution of deionised water saturated with CO2, at two different te...
The influence of a direct current (DC) stray current on the corrosion and cathodic disbondment of X80 steel coated with a polyethylene (3PE) coating in 3.5% NaCl solution was studied by immersion experiments, electrochemical tests, three-dimensional...
To analyze the causes and mechanisms affecting the fracture toughness of X80 pipeline steel welded joints against H2S, the fracture toughness of different zones of X80 pipeline steel welded joints in both air and saturated H2S solution was investigat...
This paper aims to study the relationship between the microstructure and the mechanical properties of X70 submarine pipeline steel with 40.5 mm thickness. The microstructure was examined by using optical microscopy, scanning electron microscopy and a...
Polarization curves are popularly used in many investigations; however, some wrong results are obtained when inexperienced researchers do not deeply understand electrochemical processes. In this study, the effects of the IR drop (Deviation due to I (...
Pipeline steel is a special type of steel used for transporting, for example, oil and natural gas. This study focuses on X80-grade pipeline steel modified with the addition of Nb and Nb-V at different cooling rates (air cooling or quenching) after ho...
This work presents an investigation of the effects of temperature and crack growth on cleavage fracture toughness for weld thermal simulated X80 pipeline steels in the ductile-to-brittle transition (DBT) regime. A great bulk of fracture toughness (cr...
In the current study, post-weld heat treatment (PWHT 580 °C) was used for an X80 pipeline steel-welded joint, and the fracture toughness of the welded joint was investigated using a crack tip opening displacement (CTOD) test. The relationship bet...
Fusion welding easily causes microstructural coarsening and tempering softening in the heat-affected zone (HAZ) of high-strength pipeline steel joints, which considerably deteriorates the strength and toughness. Here, X80 pipeline steel was subjected...
X65 pipeline steel is widely used in the field of offshore oil and gas exploitation due to its excellent performance. However, due to the complex environment in the ocean, X65 pipeline steel is faced with a great risk of microbial corrosion failure....
The effect of SRB and applied potential on the stress corrosion sensitivity of X80 pipeline steel was analyzed in high-pH soil simulated solution under different conditions using a slow strain rate tensile test, electrochemical test, and electronic m...
This study systematically evaluates the influence of copper (Cu) addition in gas-shielded solid wires on the microstructure and cryogenic toughness of X80 pipeline steel welds. Welds were fabricated using solid wires with varying Cu contents (0.13–0....
Pressure vessels are subjected to deterioration and damage, which can significantly reduce their strength and loading capabilities. Among several procedures nowadays available to repair damaged steel pipelines, composite-repairing systems have become...
With the rapid development of hydrogen pipelines, their safety issues have become increasingly prominent. In order to evaluate the properties of pipeline materials under a high-pressure hydrogen environment, this study investigates the hydrogen embri...
Gas–liquid intermittent flow is a kind of flow pattern that distinguishes itself from the conventional flow by the apparent non-steady feature, which causes serious corrosion issues, including localized corrosion. Although it widely exists in w...
Inclusion-induced pitting initiation mechanisms in X70 steel were investigated by scanning electron microscopy, scanning Kelvin probe force microscopy (SKPFM), immersion and electrochemical polarization tests in chloride-containing ion solutions. The...
To clarify the influence of gouge-induced altered layers on fracture initiation and load-bearing capacity of pipelines, X70 pipeline steel is taken as the research object. The geometry and partition of the altered layer are first determined by means...
In this paper, the spatial and temporal damage evolution was described during crevice corrosion through developing a two-dimensional (2-D) model. COMSOL code was used to simulate the crevice corrosion regulated by the I∙R voltage of nickel (Ni)...
This study investigates the performance degradation of X70 steel weld material in high-pressure natural gas pipelines in the Sichuan-Chongqing region and its impact on pipeline safety by investigating their behavior under multiphysics environments, i...
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