Using double ellipsoid heat source model for prediction of HAZ grain growth in GTAW of stainless steel 304

Jafarzadegan, Mostafa; Taghiabadi, R.; Mofid, Mohammad Ammar

doi:10.1016/j.mtcomm.2022.103411

Cited by 12 publications

(5 citation statements)

References 11 publications

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“…The GTAW setup was an AWS EWTh2 tungsten electrode with 2.0 mm diameter, 45° angle, 2 mm arc length and direct current. While welding, the voltage was around 10 V and the heat input from GTAW process was considered with a 75% efficiency [ 18 ]. Table 2 shows the welding conditions for all samples.…”

Section: Methodsmentioning

confidence: 99%

Increasing the Corrosion Resistance in the UNS S32750 Super Duplex Steel Welded Joints through Hybrid GTAW-Laser Welding and Nitrogen

et al. 2023

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The development of techniques to improve the welding of super duplex steels is necessary in order to ensure that the phase balance and properties of the material are not affected during this process. Hybrid arc-laser welding is a perfect combination of the advantages of both processes, producing deeper weld beads with more balanced phases than the pulsed laser process. Here, the objective was to improve the corrosion resistance of UNS S32750 weld beads by increasing the volumetric austenite percentage in the fusion zone (FZ) with a hybrid process of GTAW (gas tungsten arc welding) and pulsed laser Nd-YAG (neodymium-doped yttrium aluminum garnet). Welds were performed in bead on plate conditions with fixed laser parameters and a varying heat input introduced through the GTAW process. Additionally, welds within a nitrogen atmosphere were performed. After base metal characterization, an analysis of the FZ and heat affected zone were performed with optical microscopy, scanning electron microscopy and critical pitting tests (CPT). The synergy between the thermal input provided by the hybrid process and austenite-promoting characteristic of nitrogen led to a balanced volumetric austenite/ferrite fraction. Consequently, the results obtained in CPT tests were better than conventional welding processes, such as laser or GTAW solely.

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Section: Methodsmentioning

confidence: 99%

Increasing the Corrosion Resistance in the UNS S32750 Super Duplex Steel Welded Joints through Hybrid GTAW-Laser Welding and Nitrogen

et al. 2023

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“…Before welding, mechanical and chemical cleaning was performed with acetone to remove impurities on the surface of the welding area. The weld input heat (E) per unit weld length can be used by the following formula (1) [14]:…”

Section: Methodsmentioning

confidence: 99%

“…where I represents the welding current (A), U represents the welding voltage (V), S represents the welding speed (mm/s); η is the thermal efficiency coefficient, and the thermal efficiency coefficient of argon arc welding is taken as 0.75 [14], and E represents welding heat input (kJ/mm). The welded samples were cut from the welded joint by a wire cutting machine, as shown in Figure 2, in order to study microstructure and corrosion resistance of the welded joints.…”

Section: Methodsmentioning

confidence: 99%

Microstructure and Corrosion Resistance of Fusion Welding Zone for Duplextubes Welded with Q345R Tube Sheet under Different Welding Currents

Qian

Jin

et al. 2022

Metals

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Duplextubes are widely used in oil and gas storage and transportation, the nuclear industry, and other fields, but the welding quality of metals is an important factor affecting the use of equipment. In order to study the welding quality of S10C steel/Incoloy 825 duplextubes and Q345R tube sheet based on gas tungsten arc welding technology with a filler of ER50-6 carbon steel welding wire, the microstructure and grain size of fusion welding zone of duplextubes and tube sheet under welding currents of 150 A, 160 A, and 170 A were studied by optical microscopy and scanning electron microscopy. At the same time, the corrosion behavior of fusion welding zone after the welding was investigated in 3.5 wt.% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the metallurgical structure of the fusion welding zone was mainly composed of δ-ferrite and retained austenite. The grain size in the fusion welding zone increased with the increase of the welding current. The corrosion resistance of the fusion welding zone welded with a high welding current of 170 A was better than that with low welding currents. However, the pitting corrosion resistance of fusion welding zone with the lowest welding current of 150 A was better than that with high welding currents. This study can provide a preliminary exploration for the manufacture and applicability of duplextubes air coolers.

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“…17 Austenite grain growth can also happen in the HAZ of ASS. 20 Another serious problem is the generation of solidification cracking in the WM when the solidification mode in WM is as totally austenitic. 17,21 Hence, the weldability of stainless steels does not seem to be simple.…”

Section: Introductionmentioning

confidence: 99%

Dissimilar joining of duplex AISI 2304 stainless steel/austenitic AISI 321 stainless steel using resistance spot welding technique: Microstructural evolutions, tensile-shear properties, and fracture analysis

Badkoobeh,

Mostaan,

Rafiei

et al. 2024

Proceedings of the Institution of Mechanical Engineers, Part C:

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In this work, microstructural characteristics and mechanical performance of spot weld joints of AISI 321 austenitic stainless steel (ASS)/AISI 2304 duplex stainless steel (DSS) were experimentally assessed. The welding current and time were varied to determine their effects on the failure load/energy and mechanism of dissimilar welds. The weld metal (WM)’s microstructure had a ferritic matrix as well as a distribution of grain boundary, Widmanstätten, and transgranular austenite. Some precipitates were found in the weld. The heat-affected zone (HAZ) of the AISI 321 ASS did not experience extensive phase evolutions and only grain coarsening occurred. This led to the HAZ softening. While extensive phase transformations were identified in the HAZ of the AISI 2304 DSS. Its microstructure contained a ferrite matrix with Widmanstätten and grain boundary-type austenite. Such microstructure resulted in the HAZ strengthening. Alteration of the welding condition from 1 kA – 2 s to 3 kA – 2 s raised peak load (tensile-shear strength) from 9.7± 0.8 to 16± 1 kN and energy absorbed to fracture from 15.52 ±1 to 51.2± 2 J. Enhanced WM size was responsible for them. Finally, as welding condition reached 4 kA – 2 s, they would decrease to 14.4±1 kN and 41.76± 3 J, respectively. It arises from surface splash. Once the welding condition varied from 3 kA – 1 s to 3 kA – 3 s, the weld performance was promoted i.e., improvement of peak load from 13± 1 to 19.6± 0.5 kN and energy absorbed to fracture from 23.4±2 to 49±3 J. It results from the WM enlarged. Ultimately, welding condition of 3 kA – 4 s causes a degradation in the weld performance i.e., drop of peak load to 15.8±1 kN and energy absorbed to fracture to 33.18± 2 J. This was on account of surface splash. With reference to the fracture analysis, interfacial, single pull-out, and double pull-out fracture modes were characterized.

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Using double ellipsoid heat source model for prediction of HAZ grain growth in GTAW of stainless steel 304

Cited by 12 publications

References 11 publications

Increasing the Corrosion Resistance in the UNS S32750 Super Duplex Steel Welded Joints through Hybrid GTAW-Laser Welding and Nitrogen

Increasing the Corrosion Resistance in the UNS S32750 Super Duplex Steel Welded Joints through Hybrid GTAW-Laser Welding and Nitrogen

Microstructure and Corrosion Resistance of Fusion Welding Zone for Duplextubes Welded with Q345R Tube Sheet under Different Welding Currents

Dissimilar joining of duplex AISI 2304 stainless steel/austenitic AISI 321 stainless steel using resistance spot welding technique: Microstructural evolutions, tensile-shear properties, and fracture analysis

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