scholarly journals The investigation of the welded joints of the nitrogen containing cast austenitic steel, obtained by the manual arc welding

2020 ◽  
Vol 848 ◽  
pp. 012039
Author(s):  
V S Kostina ◽  
M V Kostina ◽  
M G Sharapov ◽  
I O Samodurov ◽  
S O Muradyan
Keyword(s):  
Austenitic Steel ◽  
Welded Joints ◽  
Arc Welding ◽  
Manual Arc Welding

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.

Methods for Defining the Concentration of Nanostructured Powders in Protective Gas and its Effect on the Microstructure of Deposit Metal

2015 ◽  
Vol 770 ◽  
pp. 28-33 ◽  
Author(s):  
M.A. Kuznetsov ◽  
Svetlana A. Barannikova ◽  
Evgeniy A. Zernin ◽  
A.V. Filonov ◽  
D.S. Kartcev
Keyword(s):  
Chemical Composition ◽  
Austenitic Steel ◽  
Arc Welding ◽  
Metal Structure ◽  
Structure Of Metal ◽  
Deposited Metal ◽  
Protective Gas ◽  
Equilibrium Microstructure ◽  
Positive Effect ◽  
Nanostructured Powders

The effect on the deposited metal structure of nanostructured modifiers introduced into the weldpool has been studied. Methods have been developed for determining the concentration of nanostructured powders of tungsten, molybdenum and Al2O3 in protective gas and for defining their optimal concentration. The influence of nanopowders on the structure of deposited metal was examined in consumable electrode arc welding employing the austenitic steel (chemical composition: C – 0,12%, Cr – 18%, Ni – 10%,Ti – 1%) as deposit and 1.2-mm welding wire manufactured from the austenitic steel (chemical composition: C – 0,12%, Cr – 18%, Ni – 9%,Ti – 1%). Addition of nanostructured powders of tungsten, molybdenum and Al2O3 to the weldpool has shown positive effect on the structure of metal in arc welding. It is shown that introducing the powders decreases dendrite size and leads to the formation of a more equilibrium microstructure of the weld.

scholarly journals The influence of manual metal arc multiple repair welding of long operated waterwall on the structure and hardness of the heat affected zone of welded joints

2017 ◽  
Vol 62 (1) ◽  
pp. 327-333 ◽  
Author(s):  
J. Pikuła ◽  
M. Łomozik ◽  
T. Pfeifer
Keyword(s):  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Power Plants ◽  
Welded Joint ◽  
Weld Bead ◽  
Boiler Steel ◽  
Metallographic Examination ◽  
Metal Arc Welding ◽  
High Degree

Abstract Welded installations failures of power plants, which are often result from a high degree of wear, requires suitable repairs. In the case of cracks formed in the weld bead of waterwall, weld bead is removed and new welded joint is prepared. However, it is associated with consecutive thermal cycles, which affect properties of heat affected zone of welded joint. This study presents the influence of multiple manual metal arc welding associated with repair activities of long operated waterwall of boiler steel on properties of repair welded joints. The work contains the results of macro and microscopic metallographic examination as well as the results of hardness measurements.

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