scholarly journals Effect of different variants of filler metal S Ni 6625 on properties and microstructure by additive layer manufactured using CMT process

2021 ◽  
Author(s):  
Manuela Zinke ◽  
Stefan Burger ◽  
Julius Arnhold ◽  
Sven Jüttner
Keyword(s):  
Weld Metal ◽  
Filler Metal ◽  
Welding Process ◽  
Travel Speed ◽  
Cold Metal Transfer ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Cold Metal ◽  
Hardness Values ◽  
Wire Feed

AbstractThe influence of arc energy and different filler metal composition on the mechanical properties and macro- and microstructure of additively welded thin-walled structures of Ni-based alloy were investigated using four different variants commercially available solid wire electrodes of type S Ni 6625. As the welding process, the Cold Metal Transfer (CMT) process was used. The heat input and cooling rate were varied by adjusting wire feed and travel speed. The results show that an increase in arc energy leads to longer t10/6 cooling times. This leads to an increase in the dendrite arm spacing and thus to a reduction in the strength values and hardness of the thin-walled structures. The higher Fe-containing variant of S Ni 6625 produces the highest strength and hardness values, while the W-alloyed solid wire electrode produces the lowest values. The porosity in the walled structures was very low, and unacceptable weld defects, hot cracks and lack of fusion did not occur. Segregations occur in all weld metal specimens. While niobium, molybdenum and titanium are the preferred segregations in the Nb-alloyed Ni 6625 type weld metal, only Mo is present in the W-alloyed Ni 6660 type weld metal.

scholarly journals Influence of arc energy and filler metal composition on the microstructure in wire arc additive manufacturing of duplex stainless steels

2020 ◽  
Vol 65 (1) ◽  
pp. 47-56
Author(s):  
Benjamin Wittig ◽  
Manuela Zinke ◽  
Sven Jüttner
Keyword(s):  
Stainless Steels ◽  
Filler Metal ◽  
Welding Process ◽  
Optical Emission ◽  
Duplex Stainless Steels ◽  
Cold Metal Transfer ◽  
Thin Walled Structures ◽  
Metal Composition ◽  
Cold Metal ◽  
Wire Arc Additive Manufacturing

AbstractThe influence of arc energy and filler metal composition on the microstructure of additively welded thin-walled structures of duplex stainless steels was investigated using different commercially available standard and superduplex solid wire electrodes commonly used today. As welding process, the cold metal transfer (CMT) process was used. The arc energy and cooling rate were varied by adjusting the wire feed and welding speed. Optical emission spectroscopy (OES) and carrier gas melt extraction (CGME) were used to determine the chemical composition of the specimens. The ferrite content was determined both by magnetic induction and by image analysis as a function of the wall height. In addition, the microsections were examined for intermetallic phases and precipitations. Moreover, corrosion tests were carried out according to ASTM G 48, Method A. The results indicate that an increase in arc energy leads to longer t12/8 cooling times. Depending on the filler metal composition, this leads to ferrite contents that are partially outside the values required according to ISO 17781. Furthermore, precipitates of secondary austenite are often found, which is attributed to the multiple reheating by the subsequent layers.

The Influence of Gas Metal Arc Welding Parameters on the Carbon Steel ss400 Grade by Using 23 Factorial Design

2011 ◽  
Vol 341-342 ◽  
pp. 11-15
Author(s):  
Prachya Peasura ◽  
Mongkol Chaisri
Keyword(s):  
Weld Metal ◽  
Feed Rate ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Travel Speed ◽  
Factors Affecting ◽  
Metal Arc Welding ◽  
Arc Welding Process ◽  
Wire Feed

The experimental observation reveals that the influence of gas metal arc welding process on physical properties. The specimen was carbon steel ss400 grade sheet of 6 mm. The experiments with 23 factorial design. The factors used in this study are voltage at 20 and 23 V, travel speed at 5 and 7 mm/sec and wire feed rate were set at 80 and 110 mm/sec. The welded specimens were tested by penetration, width of weld metal and high of weld metal. The result showed that the voltage, travel speed and wire feed rate had interaction on penetration, width of weld metal and high of weld metal at 95% confidential (P value < 0.05). Factors affecting the penetration are the most voltage of 23 V, travel speed 7 mm/sec and wire feed rate 110 mm/sec. were penetration of 31.68 mm. The width of weld metal was most at 9.9 mm. on voltage of 23 V, travel speed 5 mm/sec and wire feed rate 110 mm/sec. The factors affecting the high of weld metal are most voltage of 20 V, travel speed 5 mm/sec and wire feed rate 110 mm/sec. were penetration of 4.51 mm. This research can bring information to the foundation in choosing the appropriate parameters to gas metal arc welding process.

Welding of Internally Clad X65 Pipes With Precipitation Strengthened Ni-Based Filler Metals

2017 ◽  
Author(s):  
Graciela C. Penso ◽  
Boian T. Alexandrov
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Parameter Optimization ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Welding Parameter ◽  
Cold Metal Transfer ◽  
Alloy 625 ◽  
Metal Yield ◽  
Cold Metal

X65 steel pipes internally clad with Alloy 625 used in subsea oil extraction are normally welded together with Alloy 625 filler metal. For pipe reeling applications, DNV-OS-F101 requires pipe girth welds to overmatch base metal yield strength with 100 MPa. Since Alloy 625 filler metal does not meet this requirement, Ni-base super alloys 718 and 282 were considered as potential welding consumables for reeling applications. The solidification behavior in weld metal of these alloys diluted with Alloy 625 pipe ID cladding was evaluated using thermodynamic simulations. The response to precipitation hardening by multiple reheat cycles was studied by producing multilayer buildups with cold metal transfer (CMT) and pulsed gas metal arc welding (GMAWp) processes. Weld buildup of Alloy 718 exhibited insufficient hardening response and yield strength, while Alloy 282 met the DNV overmatch requirement. Successful narrow groove welding of X65 pipes with Alloy 282 was performed using CMT process. Welding parameter optimization allowed resolving centerline solidification cracking and lack of fusion defects. The weld metal yield strength was lower than in the multipass buildup, which was attributed to lower number of reheats in groove welding. Meeting the overmatch requirement for yield strength in Alloy 282 groove welds requires further parameter optimization.

scholarly journals Influence of post weld heat treatment on tensile properties of cold metal transfer (CMT) arc welded AA6061-T6 aluminium alloy joints

2019 ◽  
Vol 28 (1) ◽  
pp. 135-145 ◽  
Author(s):  
Addanki Ramaswamy ◽  
Sudersanan Malarvizhi ◽  
Visvalingam Balasubramanian
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Gas Metal Arc Welding ◽  
Weight Ratio ◽  
Welding Process ◽  
Metal Transfer ◽  
Post Weld Heat Treatment ◽  
Cold Metal Transfer ◽  
Cold Metal ◽  
Weld Heat

AbstractAluminium alloys of 6xxx series are widely used in the fabrication of light weight structures especially, where high strength to weight ratio and excellent weld-ability characteristics are desirable. Gas metal arc welding (GMAW) is the most predominantly used welding process in many industries due to the ease of automation. In this investigation, an attempt has been made to identify the best variant of GMAW process to overcome the problems like alloy segregation, precipitate dissolution and heat affected zone (HAZ) softening. Thin sheets of AA6061-T6 alloy were welded by cold metal transfer (CMT) and Pulsed CMT (PCMT). Among the two joints, the joint made by PCMT technique exhibited superior tensile properties due to the mechanical stirring action in the weld pool caused by forward and rearward movement of the wire along with the controllable diffusion rate at the interface caused by shorter solidification time. However, softening still exists in the welded joints. Further to increase the joint efficiency and to minimize HAZ softening, the joints were subjected to post weld heat treatment (PWHT). Approximately 10% improvement in the tensile properties had been observed in the PWHT joints due to the nucleation of strengthening precipitates in the weld metal and HAZ.

scholarly journals Effect of Filler Metal Type on Microstructure and Mechanical Properties of Fabricated NiAl Bronze Alloy Using Wire Arc Additive Manufacturing System

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 513
Author(s):  
Jae Won Kim ◽  
Jae-Deuk Kim ◽  
Jooyoung Cheon ◽  
Changwook Ji
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Metal Wire ◽  
Cold Metal Transfer ◽  
Metal Type ◽  
Cold Metal ◽  
Wire Arc Additive Manufacturing

This study observed the effect of filler metal type on mechanical properties of NAB (NiAl-bronze) material fabricated using wire arc additive manufacturing (WAAM) technology. The selection of filler metal type is must consider the field condition, mechanical properties required by customers, and economics. This study analyzed the bead shape for representative two kind of filler metal types use to maintenance and fabricated a two-dimensional bulk NAB material. The cold metal transfer (CMT) mode of gas metal arc welding (GMAW) was used. For a comparison of mechanical properties, the study obtained three specimens per welding direction from the fabricated bulk NAB material. In the tensile test, the NAB material deposited using filler metal wire A showed higher tensile strength and lower elongation (approx. +71 MPa yield strength, +107.1 MPa ultimate tensile strength, −12.4% elongation) than that deposited with filler metal wire B. The reason is that, a mixture of tangled fine α platelets and dense lamellar eutectoid α + κIII structure with β´ phases was observed in the wall made with filler metal wire A. On the other hand, the wall made with filler metal wire B was dominated by coarse α phases and lamellar eutectoid α + κIII structure in between.

Cold Metal Transfer Spot Joining of AA6061-T6 to Galvanized DP590 Under Different Modes

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
HaiYang Lei ◽  
YongBing Li ◽  
Blair E. Carlson ◽  
ZhongQin Lin
Keyword(s):  
Heat Input ◽  
Mechanical Performance ◽  
Welding Process ◽  
High Strength ◽  
Metal Transfer ◽  
Cold Metal Transfer ◽  
Spot Joining ◽  
Predrilled Hole ◽  
Joint Quality ◽  
Cold Metal

In order to meet the upcoming regulations on greenhouse gas emissions, aluminum use in the automotive industry is increasing. However, this increase is now seen as part of a multimaterial strategy. Consequently, dissimilar material joints are a reality, which poses significant challenges to conventional fusion joining processes. To address this issue, cold metal transfer (CMT) spot welding process was developed in the current study to join aluminum alloy AA6061-T6 as the top sheet to hot dip galvanized (HDG) advanced high strength steel (AHSS) DP590 as the bottom sheet. Three different welding modes, i.e., direct welding (DW) mode, plug welding (PW) mode, and edge plug welding (EPW) mode were proposed and investigated. The DW mode, having no predrilled hole in the aluminum top sheet, required concentrated heat input to melt through the Al top sheet and resulted in a severe tearing fracture, shrinkage voids, and uneven intermetallic compounds (IMC) layer along the faying surface, leading to poor joint properties. Welding with the predrilled hole, PW mode, required significantly less heat input and led to greatly reduced, albeit uneven, IMC layer thickness. However, it was found that the EPW mode could homogenize the welding heat input into the hole and thus produce the most stable welding process and best joint quality. This led to joints having an excellent joint morphology characterized by the thinnest IMC layer and consequently, best mechanical performance among the three modes.

The Effect of Sub-Zero Treatment on Mechanical Properties of GTAW Welded AA6082

2016 ◽  
Vol 852 ◽  
pp. 349-354 ◽  
Author(s):  
R. Devanathan ◽  
Sanjivi Arul ◽  
T. Venkatamuni ◽  
D. Yuvarajan ◽  
D. Christopher Selvam
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Artificial Aging ◽  
Cryogenic Treatment ◽  
Welding Process ◽  
Travel Speed ◽  
Treatment Result ◽  
Gas Tungsten Arc ◽  
Shallow Cryogenic Treatment ◽  
Hardness Values

The consequence of sub-zero treatment on the mechanical properties of welded AA6082-T6 by Gas Tungsten Arc Welding (GTAW) which in turn softens the heat concentrated welded region owing to dissolution of the strengthening precipitates. The sub-zero i.e. Shallow Cryogenic Treatment (SCT) is carried out on GTAW welded plate having a thickness of 6 mm at -77°C by varying the electrode travel speed and sub-zero treatment periods. Welded region of AA6082 were tested for hardness and microstructure by adapting three different conditions such as welded, post weld artificial aging with and without sub-zero treatment. Result revealed that the amount of softening in the welded region is indirectly proportional to electrode travel speed during welding process. It is also observed that the post weld SCT with artificial aging has increased the micro hardness values on the welded region as a consequence of the reactivation in the sequence of precipitation.

Studies on cold metal transfer welding of aluminium alloy 6061-T6 using ER 4043

2020 ◽  
Vol 234 (7) ◽  
pp. 924-937
Author(s):  
R Pramod ◽  
N Siva Shanmugam ◽  
CK Krishnadasan
Keyword(s):  
Mechanical Properties ◽  
Aluminium Alloy ◽  
Pressure Vessel ◽  
Weld Zone ◽  
Welding Process ◽  
Metal Transfer ◽  
Welding Parameter ◽  
Cold Metal Transfer ◽  
Cold Metal ◽  
Alloy 6061

Aluminium alloy 6061-T6 is utilized in aerospace industry for developing pressure vessel liner. Cold metal transfer is a promising welding process used in fabricating aluminium structures. The present work is focussed to achieve an optimum welding parameter for joining a 3.5-mm thick pressure vessel and to examine the mechanical properties and metallurgical nature of the weldment. The welded joint was evaluated as defect free using radiography test. The joint efficiency (66.61%) and measured microhardness of weldment (59.78 HV) exhibited promising results. The effect of grain coarsening in the heat affected zone (HAZ) and weld zone is attributed to the thermal gradients during welding. Dissipation of small amounts of strengthening elements Si and Mg during welding leads to reduction in mechanical properties. X-ray diffraction peaks revealed the presence of intermetallic Al–Si and Fe–Si in the weld zone. Fractography examination confirms the ductile type of failure in the fractured surface of the tensile samples.

Comparison of Hardness and Microstructures Produced Using GMAW and Hot-Wire TIG Mechanized Welding of High Strength Steels

2014 ◽  
Author(s):  
A. R. H. Midawi ◽  
E. B. F. Santos ◽  
A. P. Gerlich ◽  
R. Pistor ◽  
M. Haghshenas
Keyword(s):  
Weld Metal ◽  
Deposition Rate ◽  
Heat Input ◽  
Gas Metal Arc Welding ◽  
High Strength Steels ◽  
Travel Speed ◽  
Pressure Vessels ◽  
High Deposition Rate ◽  
Hot Wire ◽  
Wire Feed

For high productivity weld fabrication, gas metal arc welding (GMAW) is typically used since it offers a combination of high deposition rate and travel speed. Recent advances in power supply technologies have increased the deposition rates in hot-wire tungsten inert gas (HW-TIG) welding, such that it is possible to achieve parameters which may be comparable to those used in GMAW for pressure vessels and some pipeline applications. However, these two processes have drastically different deposition efficiencies and heat input characteristics. The purpose of the present study is to examine GMAW and HW-TIG bead-on-plate deposits in terms of mechanical properties, deposition rate, and heat affected zone (HAZ) thermal cycles when identical travel speed and wire feed speeds are applied with a ER90S-G filler metal. The results demonstrate that HW-TIG can be applied with comparable travel and wire feed speeds to GMAW, while providing a more uniform weld bead appearance. Based on weld metal microhardness values, it is suggested the effective heat input is lower in HW-TIG compared to GMAW, since the average hardness of the weld metal is slightly higher.

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