Improvements in the Welding Technology for Heavy Wall Pressure Vessels 2 ¼ Cr 1Mo ¼ V Low Alloy Steels

2017 ◽  
Author(s):  
Fausto Fusari ◽  
Paolo Marangoni ◽  
Michele Musti ◽  
Stefano Alberini
Keyword(s):  
Weld Joint ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Pressure Vessels ◽  
Narrow Gap ◽  
Welding Technology ◽  
Gap Technique ◽  
Single Bead ◽  
Submerged Arc

The standard practice recommended for high pressure vessels, having heavy walls, requires the implementation of weld joint preparation with narrow gap technique; this generally calls for a ‘two beads per layer’ sequence alongside the use of the submerged arc welding process. This process provides a high quality and uniformed weld joint whilst also reducing the residual stresses after welding. In refinery equipment that are subjected to high pressures and are exposed to hydrogen environment, high strength materials such as 2 1/4 Cr 1 Mo 1/4 V are commonly used. A recent study conducted on this material, and the process of submerged arc welding with narrow gap technique ‘two beads per layer,’ had identified a potential issue in complying with ASME Code specified creep resistance properties. In another setting, with regards to the properties of toughness in weld joints, other possible inconsistencies, in the narrow gap weld joint, between the weld centerline and center bead, were found. In order to overcome the deficiencies stated above, an innovative welding technology is presented in this paper which is based on the preparation of a narrower groove than the commonly used narrow gap technique. Such groove has been designed to implement the ‘single bead per layer’ approach. This paper illustrates that the use of this new technique results in improved quality of weld seams as applied in heavy wall high pressure vessels used in creep regime. The welding process considered is that of tandem submerged arc welding with two wires. The mechanical characteristics and results obtained by comparing the two techniques ‘two beads per layer’, and the new innovative one ‘single bead per layer’ will be evidenced and discussed.

Design on Cleaning Device for Slag of Narrow Gap Submerged Arc Welding

2013 ◽  
Vol 470 ◽  
pp. 404-407
Author(s):  
Wen Ming Zhang ◽  
Xiao Xu Li ◽  
Bin Wang
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Narrow Gap ◽  
Time Saving ◽  
Slag Removal ◽  
High Efficient ◽  
Cleaning Device ◽  
Welding Slag ◽  
Submerged Arc

At present, the Narrow Gap Submerged Arc Welding is an advanced welding technology. As the weld is very deep and narrow, the slag is difficult to clean and will have impact on the quality of welding seam. Therefore, a new kind of narrow gap submerged arc welding slag cleaning device is designed to clean the welding slag. It is consisted of welding walking tractor, height adjuster, slag masher, slag cleaner and slag collector. The narrow gap submerged arc welding slag removal device used for the welding process can realize the cleaning that manpower cannot finish. It is a kind of time-saving, energy-saving and high efficient welding cleaning method.

Design of CaO–SiO2–CaF2 and CaO–SiO2–Al2O3 Based Submerged Arc Fluxes for Series of Bead on Plate Pipeline Steel Welds—Effect on Carbon and Manganese Content, Grain Size and Microhardness

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Lochan Sharma ◽  
Rahul Chhibber
Keyword(s):  
Grain Size ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Pressure Vessels ◽  
Constant Current ◽  
Welding Parameters ◽  
Chemical Compositions ◽  
Optimization Approach ◽  
Submerged Arc

Submerged arc welding is mainly used to weld high thickness steel plates in various applications such as offshore oil drilling platforms, bridges, building construction, and pressure vessels. Suitable flux composition and welding parameters play an important role in determining the good bead quality, which further affects the mechanical properties of welded joint. Agglomerated fluxes were formulated based on CaO–SiO2–CaF2 and CaO–SiO2–Al2O3 flux system using constrained mixture design and extreme vertices design approach. The chemical compositions of the bead on plate have been studied using formulated fluxes. Twenty one beads on plate experiments were conducted at constant current, voltage, and welding speed using submerged arc welding process. In the present study, chemical composition, grain size, and microhardness properties of series of bead on plate weld deposits (for API 5 L X70 grade pipe line) were optimized by using multiobjective optimization approach.

scholarly journals Parametric Design on Weld Characteristics of Submerged Arc Welding Process Parameters

2018 ◽  
Vol 7 (2.23) ◽  
pp. 467
Author(s):  
Sailender Mamunuri
Keyword(s):  
Arc Welding ◽  
Parametric Design ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Pressure Vessels ◽  
Manganese Steel ◽  
Deep Penetration ◽  
Low Carbon ◽  
Joint Quality ◽  
Submerged Arc

A low carbon with manganese steel is apt for the fabrication of pressure vessels welds, which is designed for low-temperature service requirement. Submerged Arc Welding (SAW) is chosen process, due to incessant sound joint requirement and its inherent qualities like smooth bead, deep penetration and sound joint quality and reliable. SAW is renowned by huge quantity of parameters, which acts collectively influence the outputs performance, subsequently affects the joint quality. The objective is to optimize the variables parametrically for various outputs. Taguchi’s orthogonal array, which is a design of experiment, is adopted to optimize as well for their effects on desired outputs. The author modified the process by introducing ‘purging gas’ in SAW. ‘Purged’ SAW results are contrasted against the traditional ‘as-is’ of SAW. Identified the variable significance effect is through analysis of variance with their contribution. Correlations between parameters and performance outputs are established via Regression Analysis. Build models competency are checked with F-test; determined quantitatively and showed graphically, for discussion of their effects to achieve the required quality. Using confirmation tests, the models are validated and found the outcomes are in the confines.  

Design of TiO2–SiO2–MgO and SiO2–MgO–Al2O3-Based Submerged Arc Fluxes for Multipass Bead on Plate Pipeline Steel Welds

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Lochan Sharma ◽  
Rahul Chhibber
Keyword(s):  
Arc Welding ◽  
Pipeline Steel ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Pressure Vessels ◽  
Welding Parameters ◽  
Chemical Compositions ◽  
Optimization Approach ◽  
Low Alloy Steels ◽  
Submerged Arc

High strength low alloy steels are extensively used in different applications like oil and gas transmission line pipes, pressure vessels and offshore oil drilling platforms. Submerged arc welding (SAW) is mainly used to weld high thickness steel plates. Flux composition and welding parameters play an important role in determining the adequate quality and mechanical properties of the weld. Agglomerated fluxes were formulated based on TiO2–SiO2–MgO and SiO2–MgO–Al2O3 flux system using constrained mixture design and extreme vertices design approach. The chemical compositions of the bead on a plate have been studied using formulated fluxes. Twenty-one beads on plates were applied using submerged arc welding process keeping the parameters: current, voltage, and welding speed constant. Regression models were developed for bead on plate content in terms of individual, binary, and ternary mixture flux constituents for submerged arc multipass bead on plate deposition for pipeline steel (API 5 L X70). In the present study, chemical composition, grain size, and microhardness properties of the multipass bead on a plate (for API 5 L X70 grade pipeline) were optimized using multi-objective optimization approach.

Advanced submerged arc welding processes for Arctic structures and ice-going vessels

2016 ◽  
Vol 232 (1) ◽  
pp. 114-127
Author(s):  
Pavel Layus ◽  
Paul Kah ◽  
Viktor Gezha
Keyword(s):  
Case Studies ◽  
Arc Welding ◽  
Oil And Gas ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
The Arctic ◽  
Correct Selection ◽  
Advantages And Disadvantages ◽  
Welding Processes ◽  
Submerged Arc

The Arctic region is expected to play an extremely prominent role in the future of the oil and gas industry as growing demand for natural resources leads to greater exploitation of a region that holds about 25% of the world’s oil and gas reserves. It has become clear that ensuring the necessary reliability of Arctic industrial structures is highly dependent on the welding processes used and the materials employed. The main challenge for welding in Arctic conditions is prevention of the formation of brittle fractures in the weld and base material. One mitigating solution to obtain sufficiently low-transition temperatures of the weld is use of a suitable welding process with properly selected parameters. This work provides a comprehensive review with experimental study of modified submerged arc welding processes used for Arctic applications, such as narrow gap welding, multi-wire welding, and welding with metal powder additions. Case studies covered in this article describe welding of Arctic steels such as X70 12.7-mm plate by multi-wire welding technique. Advanced submerged arc welding processes are compared in terms of deposition rate and welding process operational parameters, and the advantages and disadvantages of each process with respect to low-temperature environment applications are listed. This article contributes to the field by presenting a comprehensive state-of-the-art review and case studies of the most common submerged arc welding high deposition modifications. Each modification is reviewed in detail, facilitating understanding and assisting in correct selection of appropriate welding processes and process parameters.

Influence of Thermal Simulated and Real Tandem Submerged Arc Welding Process on the Microstructure and Mechanical Properties of the Coarse Grained Heat Affected Zone

2011 ◽  
Vol 110-116 ◽  
pp. 3191-3198
Author(s):  
Sadegh Moeinifar
Keyword(s):  
Grain Boundaries ◽  
Heat Affected Zone ◽  
Heat Input ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Rolled Plate ◽  
Arc Welding Process ◽  
Submerged Arc ◽  
Tandem Submerged Arc Welding

The high-strength low-alloy microalloyed steel was procured as a hot rolled plate with accelerated cooling. The Gleeble thermal simulated process involved heating the steel specimens to the peak temperature of 1400 °C, with constant cooling rates of 3.75 °C/s and 2 °C/s to room temperature. The four-wire tandem submerged arc welding process, with different heat input, was used to generate a welded microstructure. The martensite/austenite constituent appeared in the microstructure of the heat affected zone region for all the specimens along the prior-austenite grain boundaries and between bainitic ferrite laths. The blocky-like and stringer martensite/austenite morphology were observed in the heat affected zone regions. The martensite/austenite constituents were obtained by a combination of field emission scanning electron microscopes and image analysis software The Charpy absorbed energy of specimens was assessed using Charpy impact testing at-50 °C. Brittle particles, such as martensite/austenite constituent along the grain boundaries, can make an easy path for crack propagation. Similar crack initiation sites and growth mechanism were investigated for specimens welded with different heat input values.

A Simplified Numerical Approach for Finding the Temperature Distribution in Submerged arc Welding Process

2012 ◽  
Vol 622-623 ◽  
pp. 315-318
Author(s):  
Aparesh Datta ◽  
Subodh Debbarma ◽  
Subhash Chandra Saha
Keyword(s):  
Temperature Distribution ◽  
Heat Source ◽  
Arc Welding ◽  
Welding Process ◽  
Numerical Approach ◽  
High Heat ◽  
Submerged Arc Welding ◽  
Fusion Welding ◽  
Arc Welding Process ◽  
Submerged Arc

The quality of joining has assumed a greater role in fabrication of metal in recent years, because of the development of new alloys with tremendously increased strength and toughness. Submerged arc welding is a high heat input fusion welding process in which weld is produced by moving localized heat source along the joint. The weld quality in turn affected by thermal cycle that the weldment experiences during the welding. In the present study a simple comprehensive mathematical model has been developed using a moving heat source and analyzing the temperature on one section and then the temperature distribution of other section are correlated with time delay with reference analyzed section.

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