Research on TIG welding gap corrosion resistance of X52/825 metallurgical clad pipein H2S/CO2 environment

2019 ◽  
Vol 66 (4) ◽  
pp. 412-417 ◽  
Author(s):  
Naiyan Zhang ◽  
Dezhi Zeng
Keyword(s):  
Corrosion Resistance ◽  
Transition Layer ◽  
Welding Process ◽  
Constant Load ◽  
Tig Welding ◽  
Load Test ◽  
Gas Field ◽  
Content Type ◽  
Field Solution ◽  
Composite Pipe

Purpose Bimetallic composite pipe consists of a corrosion resistance alloy (CRA) layer for corrosion resistance and carbon steel for mechanical properties, which shows a promising prospect of gathering pipeline with its effective-cost and reliable corrosion resistance. However, the corrosion resistance of composite pipe is determined by the quality of its welding gap. This paper aims to investigate the TIG welding gap corrosion resistance of X52/825 metallurgical clad pipe in H2S/CO2 environment. Design/methodology/approach Corrosion tests of X52/825 welding gap were performed in a stimulated gas field solution containing both 1 MPa CO2 and 1.5 MPa H2S at 70°C for 720 h in a self-designed high temperature and high pressure autoclave. The anti-stress corrosion cracking (SCC) performance of X52/825 clad pipe ring root welding gap was investigated in both NACE A solution and the stimulant gas field solution by four point bending testing and constant load test. Then the experiments were rerun in XX high sour gas well. In addition, the alloy diffusion and microstructure characteristics of TIG welding gap were analyzed through scanning electron microscopy and energy dispersive X-ray spectroscopy technologies. Findings The results reveal that the root welding gap is almost not corroded in the stimulant gas field solution, and no micro-cracks were observed by electron microscope. Anti-SCC test results show the root welding gap does not break, indicating a good resistance to environmental-cracking in H2S/CO2 environment. The transition layer can be obviously observed in the root welding zone, and the alloy content of transition layer is diluted. However, the transition layer does not penetrate into the inner of CRA layer, which illustrates its good anti-corrosion performance. Therefore, TIG welding technology can be well used in the welding process of composite pipe. Originality/value This paper may provide theoretical reference for manufacturing and application of clad pipe.

Optimization of CA-TIG welding parameters to predict and maximize tensile properties of super alloy 718 sheets for gas turbine applications

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tushar Sonar ◽  
Visvalingam Balasubramanian ◽  
Sudersanan Malarvizhi ◽  
Thiruvenkatam Venkateswaran ◽  
Dhenuvakonda Sivakumar
Keyword(s):  
Tensile Properties ◽  
Gas Turbine ◽  
Inconel 718 ◽  
Electron Beam Welding ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Tig Welding ◽  
Welding Parameters ◽  
Content Type ◽  
Welding Processes

Purpose The primary objective of this investigation is to optimize the constricted arc tungsten inert gas (CA-TIG) welding parameters specifically welding current (WC), arc constriction current (ACC), ACC frequency (ACCF) and CA traverse speed to maximize the tensile properties of thin Inconel 718 sheets (2 mm thick) using a statistical technique of response surface methodology and desirability function for gas turbine engine applications. Design/methodology/approach The four factor – five level central composite design (4 × 5 – CCD) matrix pertaining to the minimum number of experiments was chosen in this investigation for designing the experimental matrix. The techniques of numerical and graphical optimization were used to find the optimal conditions of CA-TIG welding parameters. Findings The thin sheets of Inconel 718 (2 mm thick) can be welded successfully using CA-TIG welding process without any defects. The joints welded using optimized conditions of CA-TIG welding parameters showed maximum of 99.20%, 94.45% and 73.5% of base metal tensile strength, yield strength and elongation. Originality/value The joints made using optimized CA-TIG welding parameters disclosed 99.20% joint efficiency which is comparatively 20%–30% superior than conventional TIG welding process and comparable to costly electron beam welding and laser beam welding processes. The parametric mathematical equations were designed to predict the tensile properties of Inconel 718 joints accurately with a confidence level of 95% and less than 4.5% error. The mathematical relationships were also developed to predict the tensile properties of joints from the grain size (secondary dendritic arm spacing-SDAS) of fusion zone microstructure.

Effect of micro-arc oxidation coating on stress corrosion behavior of AA7050

2020 ◽  
Vol 67 (2) ◽  
pp. 178-186
Author(s):  
R.G. Song ◽  
T.S. Hua ◽  
Y. Zong ◽  
S.W. Cai
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Stress Corrosion ◽  
Corrosion Behavior ◽  
Constant Load ◽  
Coated Specimen ◽  
Nacl Solution ◽  
Cracking Behavior ◽  
Content Type ◽  
Micro Arc Oxidation

Purpose This paper aims to study the effect of Micro-arc oxidation (MAO) coating on stress corrosion and electrochemical behavior of aluminum alloy. Design/methodology/approach The stress corrosion cracking behavior of 7050 aluminum alloy (AA7050) after MAO treatment was investigated in 3.5 Wt.% NaCl solution using the constant load ring. Electrochemical impedance spectroscopy (EIS) was used to evaluate the change of corrosion resistance of MAO specimens in 3.5  Wt.% NaCl solution, and appropriate equivalent circuits were established. Findings The results demonstrated that the MAO coating can improve the corrosion resistance of the AA7050 and avoid the reduction of mechanical properties caused by corrosion. In the initial stage of corrosion, the corrosion resistance of coated specimen decreased at first and then increased. In the middle and final stage of corrosion, the corrosion resistance of coated specimen decreased at first and then stabilized. Originality/value The long-term corrosion behavior of MAO specimens under stress was studied by constant load experiment and EIS. It has guiding significance for the application of MAO technology on aluminum alloy.

Prediction of heat affected zone and other mechanical properties of welded joints of HSLA A588-B of jet blast deflector

2019 ◽  
Vol 16 (4) ◽  
pp. 438-444 ◽  
Author(s):  
Utkarsh Waghmare ◽  
A.S. Dhoble ◽  
Ravindra Taiwade ◽  
Jagesvar Verma ◽  
Himanshu Vashishtha
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Welding Process ◽  
High Strength ◽  
Generation Process ◽  
Content Type ◽  
Welding Processes ◽  
Scanning Electron

Purpose The purpose of this paper is to predict and optimize the width of heat affected zone (HAZ) with better mechanical properties using suitable welding process and parameters for the fabrication of jet blast deflector (JBD) (high strength low alloy material of grade A588-B was used for fabrication) so that the JBD can sustain high exhaust parameters, because there are different welding zones formed due to the rapid cooling of weld metals. Out of the various zones of welding, HAZ remains the weakest zone in the entire weldment. Design/methodology/approach The present work describes the modeling, simulation, Modeling of three-dimensional plate and mess generation process are carried out using ICEM CFD software. FLUENT 16.0 software is used for ANSYS simulation where various models are used for analysis and results are validated with the experimental outcomes. High strength low alloy plates are welded by using shielded metal arc welding and tungsten inert gas (TIG) welding processes with two different electrodes. Optical microscopy and scanning electron microscopy were used for metallurgical study. The mechanical properties were evaluated by tensile strength test, vickers microhardness test and impact test. The corrosion resistance was evaluated by performing the potentiodynamic polarization test. Findings The present study indicated for better mechanical properties and improved corrosion resistance for TIG welded joints with type 308 L filler. Practical implications In aeronautical, defense, space and research organizations. Originality/value It can be shown from the scanning electron microscope technique that sound weld joint is produced with very good mechanical properties and joint also showed better corrosion resistance.

scholarly journals Effects of ATIG Welding on Weld Shape, Mechanical Properties, and Corrosion Resistance of 430 Ferritic Stainless Steel Alloy

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 404 ◽  
Author(s):  
Kamel Touileb ◽  
Abousoufiane Ouis ◽  
Rachid Djoudjou ◽  
Abdeljlil Chihaoui Hedhibi ◽  
Hussein Alrobei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Ferritic Stainless Steel ◽  
Welding Process ◽  
Tig Welding ◽  
Inert Gas ◽  
Steel Alloy ◽  
Stainless Steel Alloy ◽  
Mechanical Properties And Corrosion

Flux activated tungsten inert gas (ATIG) welding is a variant of tungsten inert gas (TIG) welding process with high production efficiency, high quality, low energy consumption, and low cost. The study of activating flux mechanism by increasing weld penetration has direct significance in developing flux and welding process. This study has been conducted on 430 ferritic stainless steel alloy. Design of experiment is used to get the best formulation of flux. Based on Minitab17 software, nineteen compositions of flux were prepared using the mixing method. Fluxes are combinations of three oxides (MoO3-TiO2-SiO2). Using the optimizer module available in Minitab 17 software, the best formulation was obtained to achieve the best weld depth. Hence, the obtained depth is twice greater than that achieved by conventional TIG welding. Moreover, mechanical properties and corrosion resistance have been investigated for TIG and ATIG welds respectively in tensile, impact, and hardness tests, and in potentiodynamic polarization measurement test.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

An alternative approach to thermal analysis using inverse problems in aluminum alloy welding

2017 ◽  
Vol 27 (3) ◽  
pp. 561-574 ◽  
Author(s):  
Elisan dos Santos Magalhaes ◽  
Cristiano Pedro da Silva ◽  
Ana Lúcia Fernandes Lima e Silva ◽  
Sandro Metrevelle Marcondes Lima e Silva
Keyword(s):  
Thermal Analysis ◽  
Heat Flux ◽  
Aluminum Alloy ◽  
Inverse Problems ◽  
Welding Process ◽  
Experimental Methodology ◽  
Function Technique ◽  
Content Type ◽  
Radiation Coefficient ◽  
Welding Processes

Purpose The purpose of this article is the determination of the temperature fields in a weld region has always been an obstacle to the improvement of welding processes. As an alternative, the use of inverse problems to determine the heat flux during the welding process allows an analysis of these processes. Design/methodology/approach This paper studies an alternative for the thermal analysis of the tungsten inert gas welding process on a 6,060 T5 aluminum alloy. For this purpose, a C++ code was developed, based on a transient three-dimensional heat transfer model. To estimate the amount of heat delivered to the plate, the specification function technique was used. Lab experiments were carried out to validate the methodology. A different experimental methodology is proposed to estimate the emissivity (radiation coefficient). Findings The maximum difference between experimental and numerical temperatures is lower than 5 per cent. The determined emissivity value for the aluminum 6,060 T5 presented a good agreement with literature values. The thermal fields were analyzed as function of the positive polarity. The specification function method proved to be an adequate tool for heat input estimation in welding analysis. Originality/value The proposed methodology proves to be a cheaper way to estimate the heat flux on the sample. The estimated power curves for the welding process are presented. The methodology to calculate the emissivity (radiation coefficient) was validated.

Influence of micro-nano surface texture on the hydrophobicity and corrosion resistance of a Ti6Al4V alloy surface

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bochun Xu ◽  
Nan Zou ◽  
Yunhao Jia ◽  
Chao Feng ◽  
Jiajia Bu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Titanium Alloy ◽  
Surface Texture ◽  
Surface Hydrophobicity ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Alloy Surface ◽  
Measurement Instruments ◽  
Content Type

Purpose The purpose of this paper is to study the effect of micro-nano surface texture on the corrosion resistance of a titanium alloy and investigate the correlation between corrosion resistance and hydrophobicity. Design/methodology/approach The surface of the Ti6Al4V alloy was modified by laser processing and anodizing to fabricate micro-pits, nanotubes and micro-nano surface textures. Afterward, the surface morphology, hydrophobicity and polarization curve of the samples were analyzed by cold field scanning electron microscopy, contact angle measurement instruments and a multi-channel electrochemical workstation. Findings The micro-nano surface texture can enhance the hydrophobicity of the Ti6Al4V surface, which may lead to better drag reduction to ease the friction of implants in vivo. Nevertheless, no correlation existed between surface hydrophobicity and corrosion resistance; the corrosion resistance of samples with nanotubes and high-density samples with micro-nano surface texture was extremely enhanced, indicating the similar corrosion resistance of the two. Research limitations/implications The mechanism of micro-dimples on the corrosion resistance of the micro-nano surface texture was not studied. Practical implications The density of micro-pits needs to be optimized to guarantee excellent corrosion resistance in the design of the micro-nano surface texture; otherwise, it will not fulfill the requirement of surface modification. Originality/value The influence of the micro-nano surface texture on the corrosion resistance, as well as the relationship between hydrophobicity and corrosion resistance of the titanium alloy surface, were systematically investigated for the first time. These conclusions offer new knowledge.

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