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1

Effects of heat input on mechanical properties, microstructures and thermal conductivity of copper alloy in gas tungsten arc welding technology

Azwinur, Kusuma Mukhsinun Hadi, Usman, Dharma Surya, Akhyar

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 6

316--329

EN

Copper-to-copper welding presents several complex technical challenges, primarily due to the unique properties of copper as a material. One of the main issues is copper's high thermal conductivity. The purpose of this study is to determine the mechanical properties, such as tensile strength, hardness, and thermal conductivity, of welded metal products produced using the Gas Tungsten Arc Welding (GTAW) Technology. The filler material used is ERCuNi 90/10 rods. The welding method involves variations in welding heat input, specifically 1.09 kJ/mm, 1.13 kJ/mm, and 1.2 kJ/mm. The results of the study show that welding heat input affects the mechanical properties and thermal conductivity of copper. The highest tensile strength of 180 MPa at 1.2 kJ/mm is due to the higher heat input, which improves weld penetration and strengthens the metallurgical bond, enhancing the load-bearing capacity of the welded joint. The highest hardness of 132.12 HV or 1295 MPa is found in the weld metal (WM) due to microstructural transformation during solidification. The use of ERCuNi 90/10 filler contributes to the formation of a harder dendritic structure compared to the heat-affected zone (HAZ) and base metal. Meanwhile, the highest thermal conductivity of 206.72 W/mK occurs at 1.09 kJ/mm because the lower heat input reduces the mixing of filler metal with pure copper, preserving copper’s thermal properties better than at higher heat input. At higher heat input, increased nickel dilution from the filler reduces thermal conductivity, as nickel has lower thermal conductivity than pure copper.

2

The Effects of Heat Inputs on LDSS 2101 GTAW and SMAW Weld Microstructure and Mechanical Behavior

Sharma Ambuj, Gudikandula Sravanthi

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 2

685--697

EN

The welding has been utilized to stabilize the phase fractions in the microstructure of lean duplex stainless steel (LDSS) to build massive mechanical structures. The influence of heat input on the microstructure, mechanical properties, and corrosion behavior of LDSS 2101 during the gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes is investigated in the present work. Specifically, we compared the outcomes between low heat input (LHI) at 0.85 kJ/mm and high heat input (HHI) at 1.3 kJ/mm for both welding techniques. Throughout the welding process, ER2209 filler wire was utilized. To assess the microstructural changes in the weldments, we employed an optical microscope, a scanning electron microscope, and X-ray diffraction. The results revealed that the volume phase fraction of ferrite was significantly higher in the LHI sample of GTAW compared to HHI GTAW and all SMAW welds. LHI GTAW welds have 18.2% greater Charpy impact toughness than LHI SMAW, whereas HHI GTAW has 35.7% higher than HHI SMAW specimens. The microhardness of the LHI GTAW weldments increased (from 230 ± 3.2 to 252 ± 4.8 HV10), whereas the microhardness of the LHI SMAW weldments increased (from 227 ± 2.8 to 246 ± 5.2 HV10). GTAW exhibited a fine grain structure, showcasing favorable tensile properties and higher hardness compared to SMAW. Conversely, the SMAW welds and their heat-affected regions exhibited coarse grain structures. These findings highlight the superior performance of GTAW in terms of microstructural characteristics, and mechanical properties when working with LDSS 2101 in comparison to SMAW.

3

Shielding gas oxygen and nitrogen content effects in the case of duplex stainless steel welding

Varbai Balázs

Advances in Materials Science

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2024

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Vol. 24, nr 3(81)

111--123

EN

The duplex stainless steels show improved localized corrosion resistance and strength comparing to the austenitic stainless steels. All of the duplex stainless steels solidify as pure ferrite and the double microstructure is evolving during the solid-state, diffusion driven phase transformation. In this research nitrogen and oxygen containing argon-based shielding gases were used. It was found that the nitrogen and oxygen addition significantly increased the weld metal austenite content, up to +27%. The oxygen addition also improved the weld dissolved oxygen content with up to +0.09%, and the weld penetration depth with up to +3.3 mm.

4

Influence of Groove shape on the Mechanical Properties of Welded Commercial Steel

Elfallah Saleh

Welding Technology Review

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2023

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R. 95

49--56

EN

Manufacturers always seek for quality and effective welding to stay competitive in the market. There is a continuous demand for a quick and efficient manufacturing set ups for new products. GMAW is among the welding processes that is wieldy used in the industry. Welding factors such as welding voltage, welding current, gas flow rate, filler wire size and welding speed play a significant role in determining the welding quality. Taguchi design uses optimization technique for the process of experimentation as an effort to improve productivity and enhance product quality. This study discusses the welding of commercial steel welded using GMAW. The welding was controlled by welding current, welding speed and groove shape to test their influence on the welding strength, tensile strength and hardness. X groove shape welding has obtained lower tensile strength and hardness than V groove shape as did higher welding current and lower welding speed. The results concluded that welding current welding had the highest influence on tensile strength and hardness of the welding, followed by groove shape, while the welding speed had the minimum influence. The optimized combination of welding factors is 170 A, V groove shape and 150 mm/min.

5

Welding and Corrosion Behavior of AISI H13 Welds: The Effect of Filler Metal on the Microstructural Evolutions

Varmaziar Sadegh, Mostaan Hossein, Rafiei Mahdi, Yeganeh Mahdi

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 3

839--846

EN

Welding of AISI H13 tool steel which is mainly used in mold making is difficult due to the some alloying elements and it high hardenability. The effect filler metal composition on the microstructural changes, phase evolutions, and hardness during gas tungsten arc welding of AISI H13 hot work tool steel was investigated. Corrosion resistance of each weld was studied. For this purpose, four filler metals i.e. ER 312, ER NiCrMo-3, ER 80S, and 18Ni maraging steel were supplied. Potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) were used to study the corrosion behavior of weldments. It was found the ER 80S weld showed the highest hardness owing to fully martensitic microstructure. The hardness in ER 312 and ER NiCrMo3 weld metals was noticeably lower than that of the other weld metals in which the microstructures mainly consisted of austenite phase. The results showed that the corrosion rate of ER 312 weld metal was lower than that other weld metals which is due to the high chromium content in this weld metal. The corrosion rate of ER NiCrMo-3 was lower than that of 18Ni maraging weld. The obtained results from EIS tests confirm the findings of potentiodynamic polarization tests.

6

A combined full-field imaging and metallography approach to assess the local properties of gas tungsten arc welded copper–stainless steel joints

Saranarayanan R., Lakshminarayanan A. K., Venkatraman B.

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 1

251--267

EN

The local material properties of gas tungsten arc welded (GTAW) C21000 grade copper alloy (Cu) to AISI 304 grade stainless steel (SS) joints using (ErNiCu-7) filler material are studied using a range of material characterization techniques. Electron Back Scattered Diffraction (EBSD) studies across the weld confirmed the relationships existing between the solidification modes (dendritic, planar) and their corresponding grain morphology in a high resolution. The SEM-Backscattered Electron Mode (BSE) integrated with Energy Dispersive Spectroscopy (EDS) analysis evidenced the local heterogeneous compositions across the dissimilar weld. The global and local mechanical performance of the weld joints are assessed using a conventional uniaxial tensile tests and full-field 2D-digital image correlation (DIC) respectively. The local material behaviour of the weld joint is in-line with the compositional and microstructural gradients. The weld joint has achieved the ultimate tensile strength (UTS) of 258 ± 14 MPa, which is very close to the strength of the Cu base metal (BM) and all the joints were fractured in the Cu-HAZ. Microhardness distributions measured using a spatially positioned indents found that the weld fusion zone (129.28 ± 19.22 HV) has higher hardness in compared to the Cu-BM (80.51 ± 2.58 HV).

7

Modification of the surface layer of sintered duplex stainless steels through alloying using the GTAW method

Lisiecka B., Dudek A.

Tribologia

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2018

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nr 2

81--88

EN

The demand for materials obtained using powder metallurgy (PM) is constantly increasing, especially on SDSSs, which are characterized by a two–phase structure consisting of ferrite and austenite. The main purpose of this study was to examine the effect of surface layer alloying with chromium carbide on the microstructure and tribological properties (e.g., hardness and wear resistance) of SDSSs. The multiphase sinters were prepared from two types of water–atomized steel powders: 316L and 409L. The technique of the APS method was used to deposit Cr3C2–NiAl powder on the SDSS surface. Electric arc (GTAW method) was used for surface alloying. Optical and scanning microscopy, X–ray phase analysis, and examinations of microhardness and coefficient of friction were performed in order to determine the microstructure and basic properties of SDSS after alloying. The surface alloying with Cr3C2 improves tribological properties of SDSSs such as hardness and the coefficient of friction.

PL

Zapotrzebowanie na materiały otrzymywane przy użyciu metalurgii proszków stale rośnie, szczególnie na spiekane stale duplex, które charakteryzują się dwufazową strukturą składającą się z ferrytu i austenitu. Głównym celem pracy było zbadanie wpływu stopowania warstwy wierzchniej z węglikiem chromu na mikrostrukturę i własności tribologiczne (np. twardość, odporność na zużycie) spiekanych stali. Wielofazowe spieki przygotowano z rozpylanych wodą komercyjnych proszków stalowych 316L i 409L. W celu wytworzenia powłoki z proszku Cr3C2–NiAl na powierzchni SDSS zastosowano metodę APS. Obróbkę przetopieniową spieków przeprowadzono spawalniczą metodą łukową GTAW. W celu analizy mikrostruktury i podstawowych własności spieków po stopowaniu przeprowadzono analizę z wykorzystaniem mikroskopii optycznej, skaningowej, fazową analizę rentgenowską oraz badania twardości i określenie współczynnika tarcia. Stopowanie powierzchni z Cr3C2 poprawia własności tribologiczne spieków, takie jak twardość i współczynnik tarcia.

8

Surface Treatment Proposals for the Automotive Industry by the Example of 316L Steel

Dudek A, Lisiecka B.

Multidisciplinary Aspects of Production Engineering

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2018

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Vol. 1, Iss. 1

369--376

EN

Nowadays, stainless steels are very interesting and promising materials with unique properties. They are characterized high mechanical strengths, high toughness and good corrosion resistance, so that can be used in many industrial sectors. An interesting alternative to steels obtained using the conventional methods is sintered stainless steel manufactured using the powder metallurgy technology. AISI 316L stainless steel is one of the best-known and widely used austenitic stainless steel. Modification of surface properties of stainless steels, in particular by applying the Cr3C2 coating is becoming more and more popular. The technique of atmospheric plasma spraying (APS) was used to deposit Cr3C2 - NiAl powder on stainless steel surface. In this study presents arc surface remelting of two types of stainless steel was used by GTAW method in order to improve function and usability these materials. The results of optical microscope metallographic, hardness and scratch test are presented. The main assumption for this study was to analyze the microstructure and hardness after remelting and alloying the surface of 316L steel (using GTAW method) with current intensity 50 A.

9

Wpływ energii liniowej na wybrane aspekty jakości połączeń spawanych elektrodą nietopliwą z zastosowaniem prądu pulsującego

Ostromęcka M.

Przegląd Spawalnictwa

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2017

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R. 89, nr 6

20--23

PL

Istnieje wiele opracowań naukowych, które podkreślają wpływ energii liniowej spawania na mikrostrukturę i własności złącza. Niemniej jednak znane są przypadki, gdy elementy spawane przy tej samej lub zbliżonych wartościach energii liniowej różnią się znacznie jakością. Artykuł zawiera przegląd literatury poświęconej zagadnieniom związanym z energią liniową oraz z możliwościami optymalizacji parametrów procesu przy spawaniu metodą GTAW prądem pulsującym.

EN

There are many papers and investigations concerning the major influence of heat input on microstructure and mechanical properties of welded joints. However, welded joints made with the same heat input don’t exhibit the same quality and properties in every case. The article presents the review of literature dealing with heat input issues and possibilities of optimization of pulsed current GTAW process parameters.

10

Friction stir modification of GTA 7075-T6 Al alloy weld joints: EBSD study and microstructural evolutions

Shamanian M., Mostaan H., Safari M., Szpunar J. A.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 3

574--585

EN

As known, mechanical properties of gas tungsten arc welded 7075 Al alloys are not desirable and some techniques should be utilized in order to refine the microstructure and hence to improve the mechanical properties of weld joints. In this research work, the microstructure of gas tungsten arc welded 7075 Al alloy was modified by friction stir processing. Evaluation of the tensile strength of the welded joints showed that the tensile strength of the welded joint (228 MPa) increases up to 320 MPa after friction stir processing. In addition, electron backscattered diffractometry (EBSD) was used in order to study the microstructure and grain boundary character evolutions during arc welding and friction stir processing. It was revealed that as-cast dendritic microstructure of gas tungsten arc welded joint completely disappears during friction stir processing and very fine equiaxed grains are formed in welded joints. Analysis of EBSD data showed that friction stir processing of gas tungsten arc welded joints leads to increase of specific boundaries from 0.7% up to 7.8%. In addition, fraction of high angle boundaries increases after friction stir processing which is resulted from dynamic recrystallization occurring during friction stir processing.

11

Transient finite element simulation and microstructure evolution of AA2219 weld joint using gas tungsten arc welding process

Arunkumar S., Shrikrishna A. K., Paulraj S., Devakumaran K., Kumar S. R.

Advances in Science and Technology. Research Journal

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2016

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Vol. 10, nr 31

64--73

EN

In this study we focus on finite element simulation of gas tungsten arc welding (GTAW) of AA2219 aluminum alloy and the behavioral of the microstructure before and after weld. The simulations were performed using commercial COMSOL Multiphysics software. The thermal history of the weld region was studied by initially developed mathematical model. A sweep type meshing was used and transient analysis was performed for one welding cycle. The highest temperature noted was 3568 °C during welding. The welding operation was performed on 200×100×25 mm plates. Through metallurgical characterization, it was observed that a fair copper rich cellular (CRC) network existed in the weld region. A small amount of intermetallic compounds like Al2Cu is observed through the XRD pattern.

12

Structure of MMCs with SiC Particles after Gas-tungsten Arc Welding

Przełożyńska E., Braszczyńska-Malik K. N., Mróz M.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 4

65--68

EN

The gas-tungsten arc (GTA) welding behaviors of a magnesium matrix composite reinforced with SiC particles were examined in terms of microstructure characteristics and process efficiencies. This study focused on the effects of the GTAW process parameters (like welding current in the range of 100/200 A) on the size of the fusion zone (FZ). The analyses revealed the strong influence of the GTA welding process on the width and depth of the fusion zone and also on the refinement of the microstructure in the fusion zone. Additionally, the results of dendrite arm size (DAS) measurements were presented.

13

Wpływ sposobu napawania rur kotłowych na mikrostrukturę i skład chemiczny napoin

Rozmus-Górnikowska M., Blicharski M., Kusiński J., Kusiński L., Marszycki M.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 1

31--34

PL

Celem pracy była ocena wpływu metody napawania Inconelem 625 rur kotłowych ze stali P235GH i 16Mo3 na mikrostrukturę i skład chemiczny podłoża i napoiny. Badania prowadzono na odcinkach rur kotłowych napawanych stopem niklu Inconel 625 przez czterech różnych producentów stosujących różne metody napawania: CMT, GMAW i GTAW. Wykazano, że bez względu na metodę napawania otrzymane napoiny składają się z następujących stref mikrostruktury: strefy przetopionej, strefy częściowego wymieszania oraz strefy wpływy ciepła (rys. 3). W strefie przetopionej i częściowego wymieszania obserwuje się zwiększoną zawartość Fe (rys. 4). Największą zawartością Fe przy powierzchni powłoki charakteryzują się napoiny, które mają najmniej równomierną powierzchnię wtopienia oraz najmniej gładką powierzchnię zewnętrzną. Przy najmniejszym kącie pochylenia ściegu zawartość Fe zmniejsza się najszybciej w miarę oddalania się od powierzchni wtopienia w kierunku powierzchni napoiny (rys. 6).

EN

The aim of this work was to identify the impact of the cladding method of boiler pipes from P235GH and 16Mo3 steels on the microstructure and chemical composition of substrates and coatings. The investigations were carried out on boiler pipes cladded with Inconel 625. The pipes were cladded in various conditions (CMT, GMAW and GTAW) and were delivered by different suppliers. It has been shown that regardless of the cladding method, the overlays consist of the following microstructural zones: fusion zone, partially mixed zone and heat affected zone (Fig. 3). An increased concentration of Fe was observed in the fusion zone as well as in the partially mixed zone (Fig. 4). The overlays with the least uniform fusion zone and the highest surface roughness were characterized by the highest concentration of Fe. The concentration of Fe in the overlay with the smallest bead slope decreased the quickest (Fig. 6).

14

Partially Melted Zone in Mg-Al Type Alloy After Gas-tungsten Arc Welding

Braszczyńska-Malik K. N., Przełożyńska E., Mróz M.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 2 spec.

18--21

EN

The gas-tungsten arc (GTA) welding behaviors of the commercial AZ91 magnesium alloy were examined in terms of microstructure characteristics. This study focused on the effects of the GTAW process parameters (like welding current, welding speed and method of additional cooling of the welded samples) on the size of the fusion zone (FZ) and partially melted zone (PMZ). The PMZ morphology of the eutectic regions changed from less to more divorced in the direction from the FZ to the base metal. The largest PMZ was obtained at a low welding speed (3.33 mm/s) and without additional water cooling of the samples.

15

Weldability of class 2 armor steel using gaz tungsten arc welding

Akca C., Karaaslan A.

Archives of Materials Science and Engineering

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2008

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Vol. 34, nr 2

110-112

EN

Purpose: In this study, microstructural and mechanical evaluations of class 2 armor steel after single-pass and pre-heated/single-pass welding were investigated to reveal the effect of pre-heating on heat affected zone (HAZ) in thin armor steel parts. Design/methodology/approach: In this research, class 2 armor steel parts were welded using single-pass and pre-heated/single-pass conditions to examine optimal welding parameters in relatively thin parts. Welded specimens were investigated using optical microscopy and Vickers hardness tests. Optical micrography was used to characterise transition sites of base metal, HAZ and weld zone. Hardness test was conducted to characterise homogeneity of welding in terms of mechanical properties. Findings: The results have shown that pre-heat/single-pass welding of armor steel could provide homogeneous hardness distribution along welding region. Similar microstructures and mechanical properties were found in base metal and HAZ. Practical implications: Armor steel was succesfully welded using GTAW without any defects either in weld seam or HAZ. Originality/value: Weldability of class 2 armor steel using gas tungsten acr welding was investigated.