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1

Characterization of galvanized steel-low alloy steel arc stud welded joint

Abbas S. J., Alali M., Abbas M. H., Abbas W. S.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 117, nr 2

79--85

EN

Purpose This paper investigates the possibility of successfully welding a Low Alloy Steel (LAS) stud to Galvanized Steel (GS) plate. Design/methodology/approach Arc Stud Welding (ASW) was performed on joining LAS studs to GS plates. Welding parameters were selected based on weld trails. The first tests of the welded joints were based on visual inspection for welding defects such as lack of fusion and undercut welding defects. The good quality should be free of these defects and have full weld reinforcement. Other weld qualifications included torque strength test, microhardness test, and microstructure examination. Findings The LAS studs have been successfully welded to a galvanized steel plate using the arc stud welding process. Higher welding current with adjusted welding time (800 A, 0.3 s) gave full weld reinforcement, the best joint appearance, and strength. Martensite phase was detected in the weld area and heat affected zone (HAZ), affecting the joint mechanical properties. Hardness property varied across the welded joint, and maximum hardness was recorded at the HAZ at the stud side. Hardness increased with the increasing welding current. At 800 A, welding current hardness was 10% higher than at 400 and 600 A. Torque strength was affected by weld reinforcement, and 800 A gave the best weld reinforcement that produced the highest torque strength. Research limitations/implications The main research limitation is the difficulty of welding LAS studs and GS plates. In conventional welding methods, such as gas metal arc welding, it is hard to get full weld penetration due to the geometry restrictions of the joint, which results in partial weld penetration between the studs and the plates. Furthermore, the issue of zinc evaporation during welding can be reduced by the advantage of the very high welding speed (in milliseconds) of ASW that overcomes the problem of continuous welding that usually results in the formation of harmful porosities and poor weldability. Originality/value In this research, galvanized steel plates were successfully welded to LAS studs using the ASW process. The welding parameters for this dissimilar welding joint were carefully selected. Microstructure changing due to the welding process was investigated. The joint mechanical properties were evaluated.

2

Microstructure and Mechanical Properties of AISI 1106 /AISI 1045 Steels Drawn Arc Stud Welded Joints

Algodi Samer Jasim, Salman Abdulhakeem Amer, Al-helli Ali H.

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 5

48--55

EN

Arc stud welding process was used to join a fully threaded low carbon steel AISI 1106 stud to medium carbon steel AISI 1045 plate, the effects of welding current 200, 400 A and the welding time 0.1 to 0.6 step 0.1 s on the microstructure and mechanical properties were investigated, additional parameters of adding 0.1, 1 g SiC powder and applying nano carbon layer to the welding area also included. The results demonstrate that the preferred stud welding process parameters for this system was 400 A with 0.4 s welding current and time, respectively, which has a maximum tensile strength of 583 MPa. The joints fabricated with ash and nano carbon coated at preferred welding parameters showed a slight reduction in tensile strength. The fracture of the tensile test specimen consists of three failure modes including of interface fracture between stud and plate surface due to incomplete melting at low processing parameter, pullout fracture which is featured by a hole in the plate surface and fracture at the stud shank instead of the weldment interface or heat affected zone. The microstructure of the stud and plate are characterized by equiaxed grain of ferrite and pearlite with small amount of ferrite, respectively. The fusion zone consists of fine grain of ferrite and perlite. The hardness of the fusion zone was recording 132 HV which it slightly higher than the stud hardness 128 HV and lower than that of plate of 164 HV.

3

Effect of arc stud welding parameters on the microstructure and mechanical properties of AA6061 and AA5086 aluminium alloys

Razzaq M. K. A., Abood A. N.

Journal of Achievements in Materials and Manufacturing Engineering

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2021

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Vol. 108, nr 1

24--34

EN

Purpose: This paper aims to investigate the effect of arc stud welding (ASW) process parameters on the microstructure and mechanical properties of AA6061-T6 and AA5086-H116 joint. Design/methodology/approach: ASW process was done with argon as a shielding gas. Optical microscope (OM), scanning electron microscope (SEM), and X-Ray Diffraction (XRD) were employed to investigate the influence of welding current, welding time, and gas flow-rate on the microstructure of the fusion zone (FZ). Torque strength and Microhardness tests were used to evaluate the mechanical properties of the welded joints. Findings: OM and SEM showed a cellular dendritic structure with equiaxed zone and columnar dendritic are forming at welding zone and weld interface. XRD analysis showed the precipitation of Mg2Si and Al3Mg2 in the similar and dissimilar joints. Similar ASW of AA6061-T6/AA6061-T6 recorded 19 N.m torque strength, while dissimilar welding of AA6061-T6/AA5086-H116 registered 23 N.m. With increasing heat input, grains in Fusion Zone (FZ) and Heat Affected Zone (HAZ) coarsen and the hardness in both zones decreased. The hardness of similar weldments indicated a remarkable softening of FZ, while lower hardness values were registered in HAZ of dissimilar weldments. Softening of both weldments is due to the dissolution of the strengthening precipitates. Hot cracks exist with similar weldments, while no cracks evidence with dissimilar weldments. Research limitations/implications: The main challenge in this work was how to minimize porosity level and how to avoid hot crack in the FZ. Practical implications: The application of ASW with ceramic ferrule has an important role in different production areas such as; automobile industry, aircraft applications, and appliances industry. Originality/value: Study the effect of welding current, welding time, and gas flow-rate of ASW process on microstructure and mechanical properties of AA6061-T6 and AA5086-H116 joint.

4

Study of solidification behaviour and mechanical properties of arc stud welded AISI 316L stainless steel

Abass M. H., Alali M. S., Abbas W. S., Shehab A. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 97, nr 1

5--14

EN

Purpose: This paper aims to investigate the impact of arc stud welding (ASW) process parameters on the microstructure and mechanical properties of AISI 316L stainless steel stud/plate joint. Design/methodology/approach: The weld performed using ASW machine. The influence of welding current and time on solidification mode and microstructure of the fusion zone (FZ) was investigated using optical microscope and scanning electron microscope (SEM). Microhardness and torque strength tests were utilised to evaluate the mechanical properties of the welding joint. Findings: The results showed that different solidification modes and microstructure were developed in the FZ. At 400 and 600 A welding currents with 0.2 s welding time, FZ microstructure characterised with single phase austenite or austenite as a primary phase. While with 800 A and 0.2 s, the microstructure consisted of ferrite as a primary phase. Highest hardness and maximum torque strength were recorded with 800 A. Solidification cracking was detected in the FZ at fully austenitic microstructure region. Research limitations/implications: The main challenge in this work was how to avoid the arc blow phenomenon, which is necessary to generate above 300 A. The formation of arc blow can affect negatively on mechanical and metallurgical properties of the weld. Practical implications: ASW of austenitic stainless steel are used in multiple industrial sectors such as heat exchangers, boilers, furnace, exhaust of nuclear power plant. Thus, controlling of solidification modes plays an important role in enhancing weld properties. Originality/value: Study the influence of welding current and time of ASW process on solidification modes, microstructure and mechanical properties of AISI 316 austenitic stainless steel stud/plate joint.

5

The development of arc stud welding

Kapler Mateusz, Nowacki Jerzy, Sajek Adam

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2019

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Vol. 63, No. 4

27--38

EN

The article analyses the origins and initial stages of the development of the drawn arc welding of steel studs. The analysis is focused on the evolution of welding-related professional terminology in various languages. The article presents the properties and areas of application of shear connectors – some of the most popular connectors, used particularly often in civil engineering investments.

PL

Przeprowadzono analizę historycznych początków i wstępnych etapów rozwoju technologii zgrzewania kołków stalowych łukiem ciągnionym. Dokonano przeglądu ewolucji różnojęzycznej terminologii branżowej. Przedstawiono właściwości oraz aktualne obszary zastosowań kołków gładkich z łbem – jednego z najpowszechniejszych rodzajów tego typu wyrobów we współczesnym przemyśle, wykorzystywanych szczególnie często w przedsięwzięciach inżynierii lądowej.

6

The current state of the art and the issues of the drawn arc welding of studs performed using a ceramic ferrule

Kapler Mateusz, Nowacki Jerzy, Sajek Adam

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2019

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Vol. 63, No. 2

49--56

EN

The authors performed the state-of-art analysis of recent achievements concerned with drawn arc stud welding involving the use of ceramic ferrules. The research focused on surface preparation, technological parameters, process limits and magnetic arc blow. Because of the complexity and correlations of primary electromagnetic phenomena in stud welding processes as well as due to the lack of simple and practically applicable theoretical explanation of their effect on welding results, emphasis was given to demand for industrially applicable simulation tools enabling the forecasting of stud welding results. It is believed that the above-named goal could be achieved using the non-linear regression model of an artificial neural network based on empirical data obtained on a real-time basis from simple process controlling measurement circuits.

PL

Dokonano oceny stanu zagadnienia w obszarze dotychczasowych osiągnięć w dziedzinie zgrzewania kołków łukiem ciągnionym z użyciem pierścienia ceramicznego obejmującą problematykę: przygotowania powierzchni, parametrów technologicznych, ograniczeń procesu, materiału rodzimego oraz magnetycznego ugięcia łuku. Ze względu na złożoność i wzajemne powiązanie elementarnych zjawisk elektromagnetycznych w czasie zgrzewania oraz brak łatwego do zaadoptowania w praktyce opisu teoretycznego ich wpływu na wynik zgrzewania, dostrzeżono zapotrzebowanie na narzędzia symulacyjne do prognozy wyniku zgrzewania w warunkach przemysłowych. Umożliwić to mógłby model sztucznej sieci neuronowej, który wykorzystując metody regresji, powinien sprostać tak sformułowanemu zadaniu w oparciu o dane empiryczne uzyskane w czasie rzeczywistym za pomocą prostych układów pomiarowych służących do kontroli procesu.

7

Possibilities of using production tests of the arc welding of pins in the qualifying of operators

Kapler Mateusz, Nowacki Jerzy, Sajek Adam

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2019

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Vol. 63, No. 6

17--23

EN

The study discussed in the article involved the analysis of standard-related conditions concerning the qualification testing of stud welding operators. Special attention was paid to the licensing of personnel making welds of shear connectors using drawn arc and ceramic ferrules. The authors emphasized the risk of technical standards misiterpretation and its financial consequences. The study also focused on frequent approaches to examinations by examining bodies. The final part of the article indicates the existence of legally effective methods enabling the production test-based qualification of production personnel.

PL

Dokonano analizy uwarunkowań normatywnych odnoszących się do egzaminowania kwalifikacyjnego operatorów zgrzewania łukowego kołków stalowych. Szczególną uwagę poświęcono kwestiom uprawnień personelu do wykonywania zgrzein kołków gładkich z łbem łukiem ciągnionym z poderwaniem i użyciem pierścieni ceramicznych. Podkreślono ryzyko błędnej interpretacji przepisów technicznych dotyczących badania technologii i związanych z tym konsekwencji finansowych. Przedstawiono częste podejście jednostek egzaminujących w tym zakresie. Wreszcie, wskazano na możliwość prawnie skutecznego kwalifikowania pracowników na podstawie badania produkcyjnego.