scholarly journals Application of Copper as Stabiliser in Aluminium Assisted Transfer of Titanium in Submerged Arc Welding of Carbon Steel

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1763
Author(s):  
Theresa Coetsee ◽  
Frederik De Bruin
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Weld Pool ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Molten Flux ◽  
Al Powder ◽  
Ti Powder ◽  
Submerged Arc

The element transfer of Ti from molten flux to the weld metal is limited to less than 310 ppm Ti in the submerged arc welding of carbon steel. This limitation is due to the high oxygen partial pressure prevailing at the molten flux-weld pool interface. Our previous study illustrated that the use of Al powder in combination with Ti powder improves the transfer of Ti to the weld metal to 4% Ti, whilst maintaining 509 ppm O in the weld metal. The weld metal ppm O should be controlled at 200 to 500 ppm O to maintain weld metal toughness. In this study, the addition of Cu powder with Ti and Al powder is applied to illustrate the stabiliser effect of Cu in the weld pool. The role of Cu as weld pool stabiliser is due to its decrease of the temperature required to melt Ti into the weld pool, so increasing the quantity of metal powder melted into the weld pool. The weld metal composition improved to 5.1% Ti, 3.6% Cu, and 371 ppm O. Thus, the role of Al in controlling the partial oxygen pressure at the molten flux-weld pool interface is maintained in the presence of Cu powder.

scholarly journals Reactions at the molten flux-weld pool interface in submerged arc welding

2021 ◽  
Vol 40 (1) ◽  
pp. 421-427
Author(s):  
Theresa Coetsee ◽  
Frederik De Bruin
Keyword(s):  
Weld Metal ◽  
Weld Pool ◽  
Arc Welding ◽  
Oxygen Potential ◽  
Base Plate ◽  
Submerged Arc Welding ◽  
Welding Flux ◽  
Molten Flux ◽  
Powder Addition ◽  
Submerged Arc

Abstract In submerged arc welding (SAW) of chromium (Cr) containing steels, Cr is usually added to the weld metal from the weld wire, and not from the welding flux. Manufacturing of weld wires of specific compositions is expensive and time consuming and cannot closely match all the desired alloy compositions. Therefore, the weld wire chemistry is usually over matched to the base plate composition. Better matching between the weld metal and base plate is possible if the weld metal incorporates Cr from Cr containing metal powder, instead of sourcing Cr from weld wire of limited Cr content. Because Cr is easily oxidised, the oxygen partial pressure in SAW must be controlled. This work illustrates the control of the oxygen potential at the molten flux-weld pool interface by using aluminium (Al) powder addition. The controlled oxygen potential at the molten flux-weld pool interface ensures increased Cr powder transfer into the weld pool, without interfering with oxygen transfer from the plasma arc to the weld pool. The objective of this work is to use targeted powder additions to better control Cr reactions in SAW to improve Cr metal transfer to the weld metal and maintain an acceptable level of oxygen in the weld metal.

scholarly journals Research of nanoscale titanium carbides influence on the structure and properties of weld metal in automatic submerged arc welding

2018 ◽  
Vol 226 ◽  
pp. 03029
Author(s):  
Nikolay V. Kobernik ◽  
Alexander S. Pankratov
Keyword(s):  
Titanium Carbide ◽  
Weld Metal ◽  
Weld Pool ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Structure And Properties ◽  
Cored Wire ◽  
Average Value ◽  
Submerged Arc ◽  
Primary Crystals

The influence of nanoscale refractory titanium carbide particles on the structure and properties of weld metal in automatic submerged arc welding is considered. Composite granules based on nickel were used to introduce the compound into the composition of the weld pool. Two schemes for introducing granules into the weld pool were tested, characterized by different temperature conditions: to the head part of the welding pool with the help of “ligature” and to the tail section with the help of additional filler wire. The prospects of introducing nano-sized titanium carbide into the tail part of the weld pool as part of a flux-cored wire are shown. With this method, the structure of the weld metal is observed to modify: the average size of the primary crystals of the weld metal is reduced by almost 50%. At the same time, the value of the toughness of the weld metal increases: the average value of this index increases by 36%. When titanium carbide is introduced as part of the “ligature” into the head of the weld pool, despite the effect of modifying (reducing the width of the primary crystals by 30%), the average value of the toughness of the weld metal decreases.

scholarly journals Numerical simulation of weld pool formation in submerged arc welding process

2020 ◽  
Vol 38 (4) ◽  
pp. 355-362
Author(s):  
Yosuke OGINO ◽  
Masahiro IIDA ◽  
Satoru ASAI ◽  
Shohei KOZUKI ◽  
Naoya HAYAKAWA ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Weld Pool ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Arc Welding Process ◽  
Pool Formation ◽  
Submerged Arc

scholarly journals Erratum to: Modification of Weld Metal with Tungsten Carbide and Titanium Nitride Nanoparticles in Twin Submerged Arc Welding

2019 ◽  
Vol 53 (2) ◽  
pp. 176-176
Author(s):  
N. P. Aleshin ◽  
M. V. Grigor’ev ◽  
N. V. Kobernik ◽  
R. S. Mikheev ◽  
A. S. Pankratov ◽  
...  
Keyword(s):  
Weld Metal ◽  
Titanium Nitride ◽  
Tungsten Carbide ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Submerged Arc

Modification of Weld Metal with Tungsten Carbide and Titanium Nitride Nanoparticles in Twin Submerged Arc Welding

2018 ◽  
Vol 52 (5) ◽  
pp. 440-445
Author(s):  
N. P. Aleshin ◽  
M. V. Grigor’ev ◽  
N. V. Kobernik ◽  
R. S. Mikheev ◽  
A. S. Pankratov ◽  
...  
Keyword(s):  
Weld Metal ◽  
Titanium Nitride ◽  
Tungsten Carbide ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Submerged Arc

Investigation on Deposited Metal Properties of Homemade Nickel and Nickel-Free Electrodes and Fluxes for Submerged Arc Welding of SA-508 Gr.3 Cl.1

2017 ◽  
Author(s):  
Le Mei ◽  
Junbao Zhang ◽  
Yifeng Huang ◽  
Yan Yu ◽  
Yong Jiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Arc Welding ◽  
Proton Irradiation ◽  
Submerged Arc Welding ◽  
Impact Property ◽  
Welding Material ◽  
Weld Metals ◽  
Metal Properties ◽  
Submerged Arc

Up to now, two kinds of filler metal with or without nickel element for submerged arc welding have been largely used in the reactor pressure vessel (RPV) manufacturing. In order to study the effect of nickel element on weld metal properties of SA-508 Gr.3 Cl.1, submerged arc welding material with nickel (AWS classification F8P4-EGN-F2N, F2 for short) and welding material without nickel (F8P4-EA3N-A3N, A3 for short) were used; and conventional mechanical properties, low-cycle fatigue test, and proton irradiation analysis of the two weld metals were studied. Results show that the mechanical properties of the two different weld metals are similar, except that the Charpy V-notch impact property of the weld metal with nickel is better than that without nickel; the micro-structures of F2 and A3 weld metals are both composed of ferrite base and granular bainite, but the columnar grain size of F2 weld metal is smaller relatively, which results in better impact property. In addition, the irradiated A3 weld metal has fewer dislocation loops than the irradiated F2 weld metal after the same proton irradiation dose; the irradiated weld metals both have higher micro-Vickers hardness than before.

scholarly journals Physicomathematical modeling of the formation features of fillet welds of bridge metal structures under submerged-arc welding

2020 ◽  
Vol 20 (3) ◽  
pp. 259-268
Author(s):  
A. A. Mosin ◽  
V. A. Erofeev ◽  
M. A. Sholokhov
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Fillet Welds ◽  
Maximum Efficiency ◽  
High Quality ◽  
Metal Structures ◽  
Weld Formation ◽  
Submerged Arc ◽  
Quality Formation

Introduction. The weld formation under the submerged-arc welding of bridge metal structures is investigated. The work objective is to study possibilities to increase the welding performance during the arc welding of fillet seams. Materials and Methods. Methods of computer analysis are used to optimize the technology. With their help, a physicomathematical model of fillet weld formation under the submerged-arc welding has been developed. It is based on a system of equations for thermal conductivity and equilibrium of the weld pool surface. In this system, the formation of an arc cavern is determined through the flux boiling isotherm under the action of the arc column radiation; heat transfer by the flux vapor inside the arc cavern and the influence of the spatial position on the formation of the weld pool are taken into account. Results. New mathematical relationships that describe physical phenomena under the submerged-arc welding of fillet welds are proposed. The key feature of the proposed model is in the fundamental difference between the submerged-arc welding and the gas-shielded arc welding, i.e., during submerged-arc welding, the arc burns in a gas-vapor cavern that appears due to the melting and evaporation of flux. Numerical simulation of the temperature distribution during production of the fillet welds in 1F and 2F positions is carried out. The process constraints under the single-run welding of the fillet welds are specified. It was determined that the single-run submerged-arc welding of fillet welds in 1F position exhibits high-quality formation of welds for almost the entire range of metal sheet thicknesses. During production of fillet welds in 2F position, high-quality formation is provided only for sheet thicknesses up to 8 mm. At heavy thicknesses, the formation of the seam is disrupted due to the melt flow from the vertical wall. In this case, the leg length decreases; a typical undercut is formed; so the weld will be asymmetric and less strong.Discussion and Conclusions. Comparison of the numerical analysis results with actual data on welding modes under the production of bridge metal structures shows that the existing fillet welding technologies have already reached their maximum efficiency rate. Further productivity gain is possible by forming oversized legs only with multiarc or multielectrode welding methods.

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