Dilution Control by Advanced Submerged Arc Welding

2012 ◽  
Vol 488-489 ◽  
pp. 1737-1741 ◽  
Author(s):  
Dinesh Kumar Shukla ◽  
Sunil Pandey

Dilution is a vital element in surfacing and depends on the difference in chemical composition between the weld and the parent metal, the welding process and the technique used. Metal surfacing is becoming the natural choice for reducing the consumption of expensive raw materials, processing cost and proper resource utilization. Mechanical as well as the metallurgical properties are greatly influenced by the degree of dilution. The advanced submerged arc welding (ASAW) process controls the response parameters independently and breaks the fixed relationship between the wire feed rate (W) and the welding current (I). A study was conducted to investigate the effect of process variables on the dilution during the process. The preheating of the electrode wire used in Submerged Arc Welding process (SAW) for surfacing application was done with the modification in the existing setup. Stainless steel 308L electrode wire was used on mild steel substrate to study the effect of preheating on the dilution. The results show that ASAW process controls and significantly reduces the percent dilution as compared with the conventional SAW process. ASAW process reduces the heat input, use of consumables and increased productivity, is the added advantages over the conventional process.

2014 ◽  
Vol 1043 ◽  
pp. 268-272
Author(s):  
Supphachan Rajsiri ◽  
Kanokporn Penpondee ◽  
Sittiphun Tuntawiroon

This study developed a device to solve welding problems that occur in the manufacturing of a pressure vessel for cryogenic applications under the ASME Section VIII Division 1. The cylindrical body of the vessel was assembled with short pre-fabricated cylinders and caps using submerged arc welding. The rotatable grounding electrode was mounted to the top half of the spherical cap. However, the relatively long distance between the welding and the electrode grounding locations, especially in longer vessels, restricts the flow and the distribution of the electrical current. Radiographic testing identified lack of fusion as the major reason for the restricted flow of the electrical current. This also caused additional work on welding repair. To address this issue that compromised both top-outer and bottom-inner vertical positions for circumference welding, a new grounding device was developed to reduce the flow distance. The electrical conductivity was also improved through a series of welding tests. The investigation showed that a greater average welding current increased arc stability. Radiographic testing confirmed that the vessels were welded completely suggesting the grounding device utility for increasing welding joint soundness of the circumference weldment.


2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Bashkar R ◽  
Balasubramanian V ◽  
Mani C

Submerged Arc Welding (SAW) process is used to weld large, heavy metal deposition jobs with critical requirements, and this metal joining process alone is used to weld approximately 10% of the deposited weld metal worldwide. Any augmentation in productivity of SAW process, will immensely benefit the welding industry, as this process is widely used on variety of common metals and alloys. This paper focusses on establishing relationship between welding current and productivity (in terms of weld metal deposition rate as an index), for a given filler wire diameter. Productivity rates of most common solid filler wire sizes were studied, at different preset current values, covering full current range through bead-on-plate experiments. At each preset current value, the bead was first optimized for acceptable visual quality, by varying arc travel speed and voltage, then wire feed rate (of acceptable beads) was noted. The current density, heat input and corresponding weld metal deposition rate were calculated for establishing relationships. The established relationships can be effectively used, to estimate productivity from the preset current values, for a given solid wire diameter.


Author(s):  
Pavel Layus ◽  
Paul Kah ◽  
Viktor Gezha

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.


2011 ◽  
Vol 110-116 ◽  
pp. 3191-3198
Author(s):  
Sadegh Moeinifar

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.


2012 ◽  
Vol 622-623 ◽  
pp. 315-318
Author(s):  
Aparesh Datta ◽  
Subodh Debbarma ◽  
Subhash Chandra Saha

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.


2020 ◽  
Vol 38 (4) ◽  
pp. 355-362
Author(s):  
Yosuke OGINO ◽  
Masahiro IIDA ◽  
Satoru ASAI ◽  
Shohei KOZUKI ◽  
Naoya HAYAKAWA ◽  
...  

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