Research the Effect of Stress-Pulse Regulation on the Process of Manual Arc Welding Technological Plates Made of AMg6 Alloy Sheet Material 4mm Thickness

2020 ◽  
Vol 989 ◽  
pp. 739-746
Author(s):  
Vladimir A. Mikheev ◽  
Marina M. Demidova ◽  
Roberto de Alvarenga ◽  
Victor I. Zarembo
Keyword(s):  
Residual Stresses ◽  
Transition Zone ◽  
Arc Welding ◽  
Pulse Generator ◽  
Sheet Material ◽  
Alloy Sheet ◽  
Amg6 Alloy ◽  
Stress Pulse ◽  
Manual Arc Welding ◽  
Pulse Regulation

The result of the effect of stress-pulse regulation on the process of manual arc welding with the connection of pulse generator is presented. Technology of stress-pulse regulation is accessible and easy to use: the equipment is so small that it can be applied in any convenient place. At the same time, there is a practical alignment of the microhardness of the zone of the base metal of the welded plates, the transition zone and the zone of the weld, which indicates the absence of residual stresses of the welded parts. The results of the research confirm the effectiveness and prospects stress-pulse regulation in any production.

Development of Technology for Welding Repair of Steel Housings Using a Combination of Ultrasonic Vibrations and Forced Cooling

2020 ◽  
Vol 989 ◽  
pp. 747-752
Author(s):  
Marat R. Fatkullin ◽  
Ayrat M. Fayrushin ◽  
Rif G. Rizvanov
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Weld Pool ◽  
Welded Joints ◽  
Arc Welding ◽  
Oil And Gas ◽  
Welding Process ◽  
Subsequent Heat Treatment ◽  
Manual Arc Welding ◽  
Forced Cooling

Now, one of the most pressing issues in the development of petroleum engineering is increasing the efficiency of apparatus and machines, as well as reducing material, energy and labor resources. During operation, oil-refining equipment over time destroyed by welded joints due to the impact of power and temperature loads, corrosion, and other factors. The cause of damage in welded joints of oil and gas equipment can be justified by the occurrence in them of structural heterogeneity and residual stresses during and after welding. Today manual arc welding is almost the only applicable in the repair of equipment for oil and gas processing, which require welding operations. The high temperature source of energy and the difference in deformation properties of parts are the cause of the occurrence of substantial residual stresses, which cause a change in shape, a significant decrease in strength, a decrease in the corrosion resistance of the metal, which adversely affects the durability and reliability of the structure. At present, the technology of repair with due to manual arc welding with the concomitant heating of the defective area and subsequent heat treatment is used. A complex of simultaneously proceeding processes accompanies the welding process: thermal effects on the metal in the heat-affected zone, metallurgical processes in the weld pool and crystallization of the metal in the weld pool. The repair technology presented by us, which consists in a combination of ultrasonic shock vibrations and forced cooling during the welding process, allows to improve the mechanical properties of the welded joint, as well as to refuse to carry out heating during welding and subsequent heat treatment.

The Determination of Noxes Emissions in Case of Manual Arc Welding Process with Coated Electrode

2018 ◽  
Vol 69 (7) ◽  
pp. 1826-1829
Author(s):  
Claudiu Babis ◽  
Augustin Semenescu ◽  
Oana Roxana Chivu ◽  
Maria Alina Gligor ◽  
Gabriel Iacobescu ◽  
...  
Keyword(s):  
Production System ◽  
Arc Welding ◽  
Welding Process ◽  
Practical Method ◽  
Machine Building ◽  
Short Exposure ◽  
Metal Bath ◽  
Coated Electrode ◽  
Manual Arc Welding ◽  
Arc Welding Process

The occupational risk assessment of a machine building company must cover each activity and workstation, taking into account each component of the production system (work system), each workload, work equipment and the work environment. This assessment is an extremely complicated and complex issue since the production system of such an enterprise is particularly complex and complicated. Welding assembly is a highly polluting technology process, especially of the atmosphere and soil. The formation of gases in the welding process is the result of burning of the electrodes, powders, forming the molten metal bath and making the weld seam. Welding operators are exposed to smoke and toxic gases resulting from the welding process, which can in many cases be hazardous to health. Many acute intoxications that may be caused by excessive exposure to or short exposure to smoke and gas resulting from the welding process have been studied over time. In the paper are presented the elements of risk related to the welding process and the most widespread occupational diseases that can occur in the ranges of the welding operators. The following are presented the noxious emissions from welding and are determined by a practical method the emission of noxious at welding deposition of a welding sample, using the manual arc welding process with coated electrode.

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Influence of Heat Treatment on Characteristic Behavior of Co-Based Alloy Hardfacing Coatings Deposited by Plasma Transferred Arc Welding

2011 ◽  
Vol 462-463 ◽  
pp. 593-598 ◽  
Author(s):  
Hong Xia Deng ◽  
Hui Ji Shi ◽  
Seiji Tsuruoka ◽  
Hui Chen Yu ◽  
Bin Zhong
Keyword(s):  
Residual Stresses ◽  
Vickers Hardness ◽  
Arc Welding ◽  
Steel Substrate ◽  
Heat Treatments ◽  
Material System ◽  
Coating Surface ◽  
Plasma Transferred Arc ◽  
Transferred Arc ◽  
Plasma Transferred Arc Welding

The Plasma transferred arc welding (PTAW) is widely used for hardfacing components exposed to severe conditions. Without post welding heat treatments, large tensile residual stresses remain in the hardfacing coating, which is detrimental. In this paper, a set of post welding heat treatments was evaluated for the heat-resistant steel substrate – Co-based alloy hardfacing coating system. Microstructural and mechanical properties, including the chemical phases of coating surface, the microstructure of coating surface, the Vickers hardness and the residual welding stress, were investigated before and after the heat treatments. Results revealed that during the heat treatments, some elements reprecipitated and the secondary carbide Cr23C6 was formed. After the treatments, a more regular structure and a higher Vickers hardness were obtained. Moreover, the tensile residual stresses in the coating decreased significantly. Therefore, it can be inferred that the post welding heat treatments employed in this paper were proper for this material system.

Relaxation of the stresses in welded joints in AMg6 alloy sheet

1987 ◽  
Vol 1 (2) ◽  
pp. 125-127
Author(s):  
I M Zhdanov ◽  
V N Nifantov ◽  
B V Medko ◽  
S L Dykhno
Keyword(s):  
Welded Joints ◽  
Alloy Sheet ◽  
Amg6 Alloy
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