The Experts below are selected from a list of 6381 Experts worldwide ranked by ideXlab platform
Xiaoyan Zeng - One of the best experts on this subject based on the ideXlab platform.
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Relationship Between Corrosion Resistance and Microstructure Characteristic of Single-Pass Laser-Arc Hybrid Welded Stainless Clad Steel Plate
Metallurgical and Materials Transactions A, 2019Co-Authors: Yunfei Meng, Ming Gao, Kai Kang, Xiaoyan ZengAbstract:Superior Weld Corrosion resistance to base metal (BM) of stainless clad steel plate (SCSP) was achieved by laser-arc hybrid Welding with only one pass. Under optimized parameters, the charge transfer resistance of the Weld reached 2.3 times higher than the BM, and the Corrosion current density decreased to 70 pct of the BM. Considering the inhomogeneity caused by dendrites, an equivalent Cr content, i.e., [Cr]E, was proposed to establish a new relationship between the Corrosion resistance and the microstructure characteristic of the SCSP hybrid Weld. It suggests better Weld Corrosion resistance than the BM is obtained when the [Cr]E ≥ 15.5 pct. The results would be suitable to predict the Corrosion resistance of the SCSP Weld, and promote its industrial application.
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effects of alloying element on Weld characterization of laser arc hybrid Welding of pure copper
Optics and Laser Technology, 2018Co-Authors: Mengcheng Gong, Xiaoyan ZengAbstract:Abstract Effects of alloying elements of Si and Sn on Weld characterizations of laser-arc hybrid Welded pure copper (Cu) with thickness of 2 mm was studied in detail by using different wires. The Weld microstructure was analyzed, and the mechanical properties (micro-hardness and tensile property), conductivity and Corrosion resistance were tested. The results showed that the alloying elements benefit the growth of column grains within Weld fusion zone (FZ), increase the ultimate tensile strength (UTS) of the FZ and Weld Corrosion resistance, and decrease Weld conductivity. The mechanisms were discussed according to the results.
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Microstructures and properties of single-pass laser-arc hybrid Welded stainless clad steel plate
Journal of Manufacturing Processes, 2018Co-Authors: Yunfei Meng, Ming Gao, Kai Kang, Xiaoyan ZengAbstract:Abstract The effects of wire Cr content on the microstructures and properties of single-pass laser-arc hybrid Welded stainless clad steel plate (SCSP) were studied. Increasing Cr content strengthened the Weld Corrosion resistance, but it increased the average grain size of fusion zone (FZ), deteriorated the Weld microstructure uniformity, and weakened the Weld mechanical property. The variations of the Weld properties were closely related to the microstructure changes. The solidification mode and microstructure transformation mechanism of the SCSP hybrid Weld were clarified based on the quantitative calculation of the Cr and Ni equivalent contents (Creq and Nieq) after the mixing of the wire and base metal. The calculated ratio of the Creq and Nieq (θ) could effectively predict the solidification mode and microstructure of the SCSP Weld, and then indicate its properties. The skeletal and acicular ferrites formed in the FZ when the θ was larger than 1.35, which benefited to strengthen the SCSP Weld.
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effects of laser arc distance on Corrosion behavior of single pass hybrid Welded stainless clad steel plate
Materials & Design, 2017Co-Authors: Kai Kang, Ming Gao, Yosuke Kawahito, Xiaoyan ZengAbstract:Abstract Single pass laser-arc hybrid Welding of stainless clad steel plate was first carried out to develop alternatives to multi-pass Welding with low efficient or single pass Welding with poor Corrosion resistance. The results demonstrated that the Weld Corrosion resistance increased with the increase of laser-arc distance (DLA), and the Corrosion morphologies changed from big and deep ‘nail’ pits to small and shallow hemispherical pits. The Weld with nearly equal Corrosion resistance to the base metal (BM) could be obtained at the DLA of 9 mm, where the charge transfer resistance increased to 89% of the BM and the Corrosion current density decreased by ten times to close to the BM, only 0.13 μA·cm− 2 lower. The Corrosion resistance improvement had a good agreement with the microstructure homogenization and the increase of Cr content. The microstructure formation was discussed by the molten pool behavior and the laser-arc interaction. The Corrosion resistance improvement was explained by the formation and damage mechanism of the passive film.
Ming Gao - One of the best experts on this subject based on the ideXlab platform.
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Relationship Between Corrosion Resistance and Microstructure Characteristic of Single-Pass Laser-Arc Hybrid Welded Stainless Clad Steel Plate
Metallurgical and Materials Transactions A, 2019Co-Authors: Yunfei Meng, Ming Gao, Kai Kang, Xiaoyan ZengAbstract:Superior Weld Corrosion resistance to base metal (BM) of stainless clad steel plate (SCSP) was achieved by laser-arc hybrid Welding with only one pass. Under optimized parameters, the charge transfer resistance of the Weld reached 2.3 times higher than the BM, and the Corrosion current density decreased to 70 pct of the BM. Considering the inhomogeneity caused by dendrites, an equivalent Cr content, i.e., [Cr]E, was proposed to establish a new relationship between the Corrosion resistance and the microstructure characteristic of the SCSP hybrid Weld. It suggests better Weld Corrosion resistance than the BM is obtained when the [Cr]E ≥ 15.5 pct. The results would be suitable to predict the Corrosion resistance of the SCSP Weld, and promote its industrial application.
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Microstructures and properties of single-pass laser-arc hybrid Welded stainless clad steel plate
Journal of Manufacturing Processes, 2018Co-Authors: Yunfei Meng, Ming Gao, Kai Kang, Xiaoyan ZengAbstract:Abstract The effects of wire Cr content on the microstructures and properties of single-pass laser-arc hybrid Welded stainless clad steel plate (SCSP) were studied. Increasing Cr content strengthened the Weld Corrosion resistance, but it increased the average grain size of fusion zone (FZ), deteriorated the Weld microstructure uniformity, and weakened the Weld mechanical property. The variations of the Weld properties were closely related to the microstructure changes. The solidification mode and microstructure transformation mechanism of the SCSP hybrid Weld were clarified based on the quantitative calculation of the Cr and Ni equivalent contents (Creq and Nieq) after the mixing of the wire and base metal. The calculated ratio of the Creq and Nieq (θ) could effectively predict the solidification mode and microstructure of the SCSP Weld, and then indicate its properties. The skeletal and acicular ferrites formed in the FZ when the θ was larger than 1.35, which benefited to strengthen the SCSP Weld.
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effects of laser arc distance on Corrosion behavior of single pass hybrid Welded stainless clad steel plate
Materials & Design, 2017Co-Authors: Kai Kang, Ming Gao, Yosuke Kawahito, Xiaoyan ZengAbstract:Abstract Single pass laser-arc hybrid Welding of stainless clad steel plate was first carried out to develop alternatives to multi-pass Welding with low efficient or single pass Welding with poor Corrosion resistance. The results demonstrated that the Weld Corrosion resistance increased with the increase of laser-arc distance (DLA), and the Corrosion morphologies changed from big and deep ‘nail’ pits to small and shallow hemispherical pits. The Weld with nearly equal Corrosion resistance to the base metal (BM) could be obtained at the DLA of 9 mm, where the charge transfer resistance increased to 89% of the BM and the Corrosion current density decreased by ten times to close to the BM, only 0.13 μA·cm− 2 lower. The Corrosion resistance improvement had a good agreement with the microstructure homogenization and the increase of Cr content. The microstructure formation was discussed by the molten pool behavior and the laser-arc interaction. The Corrosion resistance improvement was explained by the formation and damage mechanism of the passive film.
Anne Neville - One of the best experts on this subject based on the ideXlab platform.
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Determining the Behavior of Sulfur Compounds in Controlling Preferential Weld Corrosion in CO 2 - saturated Brine
Corrosion, 2014Co-Authors: Richard Barker, Michael Bryant, Frederick Pessu, Anne NevilleAbstract:This paper presents the application of white light interferometry as a new complimentary technique in addition to zero resistance ammetry (ZRA) and the linear polarization resistance (LPR) technique to determine regions of selective attack on 1% Ni Welds in CO2-saturated environments. Un-segmented electrodes consisting of a parent material, heat affected zone (HAZ) and Weld were subjected to long duration immersion tests and subsequently 3D profiled using white light interferometry to assess which regions (if any) preferentially corroded. In parallel tests, a multi-array electrode was introduced, consisting of a segmented carbon steel parent material, HAZ and 1% Ni Weld. Each electrode facilitated electrical connections, allowing each individual segmented to be electrically connected externally via a potentiostat, simulating a fully un-segmented sample. A multi-channel ZRA arrangement was adopted to simultaneously quantify the current transfer between the areas of interest. The intrinsic Corrosion rates of the materials were also measured using the linear polarization resistance technique in an effort to determine whether the total Corrosion rates of each Weld region could be calculated and compared with the profilometry data. One week experiments were conducted in 3 wt.% NaCl uninhibited and inhibited (5 ppm of 2-mercaptoethanol and 5 ppm sodium thiosulphate) environments. The profiles obtained are further supplemented with scanning electron microscopy (SEM) images to assess the surface damage in more detail. The results indicate that white light interferometry can act as a valuable complementary technique by helping understand the extent of localized/pitting Corrosion on the material surface. The technique also allows verification of the relative differences in total Corrosion rates of the parent, HAZ and Weld, thus helping to validate the electrochemical responses obtained. Finally, a case study is presented to demonstrate how the application of white light interferometry was used to determine the propensity for PWC to occur on a North Sea pipeline.
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the influence of high shear and sand impingement on preferential Weld Corrosion of carbon steel pipework in co2 saturated environments
Tribology International, 2013Co-Authors: Richard Barker, Anne NevilleAbstract:Abstract Preferential Weld Corrosion (PWC) has proved problematic for the oil and gas industry for a number of years. Although the effect of high flow rates on PWC in inhibited CO 2 -saturated solutions has been studied by authors, the consideration of a higher, localised turbulence over the Weld material and the implications this has on PWC appears minimal. This work considers this very effect, along with developing an understanding of the threats posed to Weld integrity by sand particle presence in the process fluid using a submerged impinging jet (SIJ) apparatus. Experiments were conducted using a commercially available film-forming oilfield Corrosion inhibitor which was evaluated in both flow-induced Corrosion and erosion–Corrosion environments in its ability to control PWC. The SIJ setup allowed control over the individual flow velocities at each nozzle, meaning shear stress could be intensified over the 1% Ni–0.25% Mo Weld material to simulate localised turbulence at the sample surface. Galvanic current and mixed potential measurements were performed to ascertain changes in galvanic interactions between the two materials. The work demonstrates that localised turbulence over internal Weld beads and the presence of sand within oil and gas systems can influence PWC in certain environments.
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Assessment of Preferential Weld Corrosion of Carbon Steel Pipework in CO2-Saturated Flow-Induced Corrosion Environments
CORROSION, 2013Co-Authors: Richard Barker, Anne Neville, Susan CushnaghanAbstract:Preferential Weld Corrosion (PWC) has posed a problem to the oil and gas industry for a number of years. The general consensus from authors is that environmental effects take precedence over the we...
Zhicao Feng - One of the best experts on this subject based on the ideXlab platform.
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Recommend design of filler metal to minimize carbon steel Weld metal preferential Corrosion in CO 2 -saturated oilfield produced water
Applied Surface Science, 2016Co-Authors: Lu Yongxin, Hongyang Jing, Yongdian Han, Zhicao FengAbstract:The paper proposes a recommend design for the alloying elements in the filler metal to minimize preferential Weld Corrosion of carbon steel. The tensile and Corrosion resistance properties of the Weld metal are considerably improved by using a filler metal containing alloying elements according to the recommended design. Analysis of the morphology and composition of Corrosion products on Weld metals showed that the common Weld metal suffered severe localized Corrosion, whereas the Weld metal with the alloying elements exhibited uniform Corrosion. Based on these results, a tentative mechanism of CO2 Corrosion resistance for both Weld metals has been proposed.
Sachi Maheshwari - One of the best experts on this subject based on the ideXlab platform.
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a review on Welding of high strength oil and gas pipeline steels
Journal of Natural Gas Science and Engineering, 2017Co-Authors: Satish Kuma Sharma, Sachi MaheshwariAbstract:Abstract Owing to the findings of new locations for crude oil and natural gas, the need of high strength materials that can be used for pipes and their joining has gained paramount importance. Welded pipes have to bear internal fluid pressure in addition to the adverse external conditions. Welding of high strength pipeline materials is also a challenge for engineers in construction of pipes as well as oil and gas transportation lines. To increase reliability and profitability in this industry, effective Welding techniques are needed for these materials. To understand the issues related with the Welding of these high strength steels, requirements of chemical composition and mechanical properties for these materials are discussed in detail. Through this review article, an attempt has been made to critically analyse the issues and challenges associated with the Weldability of high strength pipeline materials. Status of current research for Weld Corrosion, hydrogen embrittlement, residual stress, Weld repairing and deteriorated heat affected zone is also summarized. Current development trends are discussed with a view to envisage future directions. Findings of this review work emphasize the need to shift the research focus from currently used grades X65, X70 and X80 to the advanced grades X90, X100 and X120.