Dissimilar Metal Welds Research Articles

Evaluation of metallurgical and mechanical properties in dissimilar welding of Monel 400 and Hastelloy C-2000 using single and double pulse gas metal arc welding techniques

Investigation of the single pulse gas metal arc welding (SPGMAW) compared with double pulse gas metal arc welding (DPGMAW) methods for welding Monel 400 and Hastelloy C-2000, two materials with very different welding properties. To determine the best welding parameters and technique, this study set out to evaluate the metallurgical and mechanical characteristics of the weld joints. While previous studies have examined individual welding methods for similar or dissimilar materials, limited attention has been given to the impact of pulsing strategies. This work uniquely assesses the suitability of DPGMAW for welding Monel 400 and Hastelloy C-2000, offering a detailed analysis of weld interface microstructure, residual stresses, and mechanical properties. Analysis of the weld interface microstructure by optical and scanning electron microscopy showed that DPGMAW resulted in a finer and more homogeneous grain structure than SPGMAW. The heat affected zone (HAZ) in the DPGMAW samples showed reduced grain growth, which is attributed to the cyclic thermal input characteristic of the double pulse technique. Mechanical testing confirmed superior properties for DPGMAW weldments, including higher tensile strength, elongation, and uniform hardness distribution. Impact toughness tests showed greater energy absorption, indicating better resistance to brittle fracture. The refined microstructure contributed to enhanced mechanical performance. The findings suggest that DPGMAW is a more effective welding technique for joining Monel 400 and Hastelloy C-2000, providing improved metallurgical and mechanical properties. Additionally, residual stress measurements showed lower tensile residual stresses in the DPGMAW weldments compared to SPGMAW, which is beneficial for the long-term performance and reliability of the weldments. These findings demonstrate, for the first time, the advantages of DPGMAW in achieving high-performance welds for Monel 400–Hastelloy C-2000 joints, making it a promising technique for critical applications involving dissimilar metal welding.

Autogenous laser welded joint of Inconel 625 and AISI 316L steel: Microstructure and mechanical properties

The study focused on a dissimilar laser-welded joint between heat-resistant AISI 316L stainless steel and Inconel 625. It included optical and scanning electron microscopy (SEM) analysis of the weld metal, heat affected zone, and fusion interface, along with microhardness measurements, Charpy impact toughness tests, and tensile property evaluations at room and elevated temperatures. Microstructural examination revealed an asymmetric solidification behavior across the weld metal of the dissimilar welded joint. On AISI 316L side, weld metal near the fusion boundary predominantly exhibited cellular and columnar solidification structure. In contrast, Inconel 625 side showed the formation of columnar dendritic structures, indicating directional solidification driven by thermal gradients and compositional differences between the base metals. Within the inter-dendritic regions and along cellular grain boundaries of the weld metal, the precipitation of Laves phases and NbC was evident in various morphologies including spherical, chain-like, and rectangular, suggesting non-equilibrium segregation during rapid solidification. The tensile strength of the dissimilar weld metal was significantly lower than that of Inconel 625 base metals and close to AISI 316L steel base metal, with an average ultimate tensile strength of 600 MPa and elongation of 46%. The tensile strength of the welded joint was measured to be 336 MPa at 650 °C and 280 MPa at 700 °C. Similarly, Charpy impact testing at room temperature revealed lower energy absorption in weld metal compared to the base metals, with an average toughness value of 72 J.

Intermediate Layer in Titanium/Steel Dissimilar Welding: A Review

Dissimilar metal joints comprising titanium and steel are widely utilized in industrial fields. To mitigate the potential deterioration of welded joints resulting from the formation of brittle intermetallic compounds (IMCs) due to the direct contact between titanium and steel, an intermediary metal layer is typically employed during the welding process to prevent or restrict the generation of IMCs and thereby realize joints with superior mechanical properties. This study presents a comprehensive analysis of literature studies and technical processes pertaining to titanium/steel welding over the last decade. It provides a systematic review of the research progress in the dissimilar metal welding of titanium/steel systems with a particular focus on the utilization of intermediate layer metals. In addition, it discusses the existing challenges in the field of titanium/steel dissimilar metal welding in this area. Finally, this review critically analyzes emerging strategies for dissimilar material joining and proposes that in situ high‐entropy alloying of welded joints via fusion welding processes, guided by entropy design principles, represents a transformative pathway for next‐generation heterogeneous material welding technologies.

Study on element mixing of titanium-stainless steel dissimilar metal welding pool and its effect on joint properties in nanosecond laser welding

Study on element mixing of titanium-stainless steel dissimilar metal welding pool and its effect on joint properties in nanosecond laser welding

Development of hybrid ANN-GA and RSM models for optimizing mechanical properties in SS400-SUS304 welds

Dissimilar metal welding, such as joining SS400 and SUS304, presents significant challenges due to differences in metallurgical and thermal properties, often leading to internal stresses, cracking, and reduced joint durability. These disparities compromise mechanical performance, necessitating advanced optimization techniques. This study applies a hybrid optimization approach integrating Artificial Neural Networks (ANN), Genetic Algorithms (GA), and Response Surface Methodology (RSM) to optimize Gas Metal Arc Welding (GMAW) parameters for enhanced tensile strength and hardness. Experimental conditions involved welding currents of 80–120 A, speeds of 200–400 mm/min, and a shielding gas composition of 95 % argon and 5 % oxygen. The ANN-GA model demonstrated superior predictive accuracy, with RMSE values of 236.43 N for tensile strength and 2.27 HV for hardness. Maximum tensile strength and hardness of 16,302 N and 192.08 HV, respectively, were achieved at specific parameter combinations. The ANN-GA-optimized conditions of 107.10 A and 336.38 mm/min provided a balance between strength and hardness, significantly improving weld quality. RSM revealed interactions among welding parameters but exhibited lower predictive accuracy than ANN-GA. This study highlights the effectiveness of ANN-GA in capturing nonlinear welding relationships, offering a robust framework for optimizing welding processes. The optimized parameters enhance weld quality, reduce costs, and improve operational efficiency in industrial welding applications

Influences of Filler Metals on Microstructure and Mechanical Characteristics of GTA Weld Carbon Steel/ Austenitic Stainless Steel Dissimilar Metal Joint

The structural requirements for power plants service environment characteristically demand for welded joints of multi-materials and hybrid structures. The excellent corrosion resistance of AISI 316 and API 5L X56; the negligible response of AISI 316 to magnetic field and the economic viability of API 5L X56 makes these alloy considerable as hybrid structure in power plants application. Also, the appropriate filler metals that will support the intended properties for the proposed service condition is critical for a quality Dissimilar metal welded joint (DMWJ). This study investigates the effect of filler metals on the microstructural and mechanical properties of DMWJ produced from carbon steel API 5L X56 and stainless steel 316L using Gas Tungsten Arc (GTA) welding techniques. The DMWJs were produced using duplex ER2209, austenitic ER308 and austenitic ER316 grade filler. Microstructural evaluation of the joints revealed macro segregation occurrence and formation of type II boundaries at the interface of API 5L X56 steel. In tension tests, the ER2209 filler metal joints showed the maximum ultimate tensile strength values compared to the welds of other filler metals. The average yield strengths of the three welded joints were higher than those of AISI 316L base metal (BM), which indicates that the yield strength of all the welded joints can satisfy the minimum requirements of engineering application for the API 5L X56/AISI 316L DMWJs. The highest hardness value of about 237.5Hv was obtained in the ER2209 filler metal weld. Keywords: AISI 316; API 5L X56; Dissimilar metal welds; GTAW; Mechanical properties; Microstructural characteristics.

Laser keyhole welding of dissimilar metals with spiral contours: Metal mixing, microstructure, and mechanical strength

Laser keyhole welding of dissimilar metals with spiral contours: Metal mixing, microstructure, and mechanical strength

Microstructure and mechanical properties of dissimilar ferritic (S355)–austenitic (AISI 304) steel joints welded by robotic GMAW

Abstract In applications requiring high corrosion resistance, it is crucial to utilize dissimilar welding techniques that incorporate structural steels in critical areas to reduce costs, rather than constructing the entire structure from high-cost stainless steels. Ferritic steels are often preferred due to their higher strength compared to stainless steels. In this study, Gas Metal Arc Welding (GMAW) was performed on 12 mm thick S355 structural steel and AISI 304 austenitic stainless steel using SG307 austenitic filler metal. Following welding operations with three different heat inputs, macrostructural assessments were carried out according to the EN ISO5817:2023(E) standard on the welds deemed successful based on nondestructive tests. Microstructural characterization, microhardness tests, tensile test, and impact tests (performed by notching different regions of the weld joint) were also conducted. The results demonstrated that undesirable changes in mechanical properties due to microstructural transformations in the welding of carbon steels with austenitic stainless steels can be mitigated with the correct parameters and proper filler metal selection. Thus, the mechanical properties required to ensure the expected performance of the welded structure were successfully achieved. Results revealed that the dissimilar joint efficiency with respect to yield strength of ferritic steel was calculated as 103.77 % and 175.42 % for austenitic AISI 304 steel. The impact toughness test results for the heat-affected zone (HAZ) of S355 steel showed satisfactory levels. Although the dissimilar weld metal region exhibited lower toughness values, they remained above 100 J.

Corrigendum to ‘Residual stress assessment for dissimilar metal welds in nuclear power plant’ [Int. J. Pres. Ves. Pip. Volume 206, December 2023, 105018

Corrigendum to ‘Residual stress assessment for dissimilar metal welds in nuclear power plant’ [Int. J. Pres. Ves. Pip. Volume 206, December 2023, 105018

Experimental Study on Laser Lap Welding of Aluminum–Steel with Pre-Fabricated Copper–Nickel Binary Coating

In order to solve the problem of poor weld quality caused by brittle metal compounds in the welding of dissimilar metals between aluminum and steel, a pre-welding treatment method of prefabricated copper–nickel binary coating between aluminum and steel has been proposed. Laser lap welding tests and weld performance tests were conducted using 6061 aluminum alloy and DP590 duplex steel with a thickness of 0.5 mm as base materials, with steel on top and aluminum on bottom. The research results indicate that the prefabricated copper–nickel binary coating can effectively suppress the formation of brittle phase compounds of Fe and Al; the increase of copper and nickel elements is beneficial for the formation of tough compounds such as (Fe, Cu, Ni)3Al, (Fe, Cu, Ni)Al3, and CuAl5 in the weld zone; when the thickness of the copper coating is 155 μm and the thickness of the nickel coating is 110 μm, the mechanical properties of the aluminum steel lap welding seam are the best, and the maximum shear force that can be withstood is 208.09 N, which is 56% higher than uncoated sample.

Microstructure and Properties of Resistance Element Welded Joints of DP780 Steel and 6061 Aluminum Alloy

This study developed a metallurgical and mechanical hybrid resistance element welding (REW) method to fabricate lightweight Al/steel joints between 2.0 mm 6061 aluminum alloy and 1.2 mm DP780 steel, addressing critical challenges of interfacial intermetallic compounds (IMC layer thickness: 4.6–8.3 μm) in dissimilar metal welding. In addition, the scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and electron probe microanalysis (EPMA) were used to observe the microstructure characteristics and element distribution. The lath martensite and solidification microstructure were observed in the steel-nugget zone and Al-nugget zone, respectively. Furthermore, the microhardness distribution, volume fraction of the α phase, tensile–shear load, and failure mode of REWed joint were studied. Process optimization demonstrated welding current’s pivotal role in joint performance, achieving a maximum tensile–shear load of 6914.1 N under 10 kA conditions with a button pull-out failure (BPF) mechanism.

Characterisation of dissimilar metal weldments of titanium alloys Ti-64 and Ti-6246 made using electron beam and rotary friction welding

Abstract Welding of dissimilar Titanium alloys viz. Ti-64 and Ti-6246 by fusion processes is challenging due to their different physical properties. Such alloys find applications in turbine disks and blades. The alloys were welded using Electron Beam Welding (EBW) and Rotary Friction Welding (RFW) processes. In this paper, metallurgical and mechanical properties of welded joints between the Titanium alloys were examined and reported. Microstructures, electron back scattered diffraction (EBSD) analysis, and residual stresses were also examined. The EBW weld was free of defects such as porosity and inclusions. Furthermore, RFW weld was also free of any defects. SEM and EBSD analysis also support this conclusion. The coarse columnar beta grains with thin needle-like alpha can be observed in the fusion zone of the EBW weldments. The grains appeared to have been refined in the deformation zone (DZ) due to dynamic recrystallization (DRX) in the RFW joints. The yield and ultimate tensile strengths of EBW weldments were 977 MPa and 1051 MPa respectively. While that of RFW weldments, 960 MPa and 1039 MPa. The percent elongation of the EBW weldments and RFW weldments was 14.2 and 10.28 respectively. The welds were stronger than the base metal in both the weldments as the fracture occurred in the Ti-64 base metal and not in the weld during tensile test. The microhardness of the fusion zone of EBW weldments was approximately 430 HV to 460 HV. While that of weld nugget of RFW weldments was 380 HV. The mechanical properties indicate that either of the welding processes is suitable for welding the alloys.


Design strategies for enhancing strength and toughness in ultrasonic welding of dissimilar metals: A review

Design strategies for enhancing strength and toughness in ultrasonic welding of dissimilar metals: A review

Rotary Inertia Friction Welding of Dissimilar High- Strength 422 Martensitic Stainless Steel and 4140 Low Alloy Steel for Heavy-Duty Engine Piston Fabrication

AISI 422 martensitic stainless steel with superior hightemperature performance (oxidation resistance and strength) is under evaluation for replacing current heavy-duty piston crown materials, AISI 4140 martensitic steel and microalloyed steel (MAS) 38MnSiVS5, to fabricate a multimaterial piston (Refs. 1, 2). This multimaterial piston concept further improved power density and fuel economy by allowing heavyduty diesel engines to operate at higher temperatures and pressures (Ref. 3). Joining AISI 422 steel piston crowns with AISI 4140 steel piston skirts is a key manufacturing step for this multimaterial piston. However, the significant differences in strength, elevated temperature flow stress, alloy chemistry, and temper resistance between these two martensitic steels cause some weldability issues (cracking) and metallurgical challenges (alloying element migration/segregation) when using conventional fusion-based welding processes (Refs. 4–6). Rotary inertia friction welding (RIFW), a solid-state welding process, has been the preferred method to join 4140 crowns to 4140 skirts (and MAS crowns to MAS skirts) in high-volume production of current heavy-duty diesel engine pistons. It has been used to join these two materials with relatively comparable alloy chemistry to fabricate pistons with MAS skirts and 4140 crowns. Meanwhile, RIFW has also been a preferred method of dissimilar metal welding (Refs. 7, 8). However, RIFW of dissimilar high-strength martensitic steels has yet to be widely pursued. The interfacial microstructure complexities created by the thermomechanical process and highly nonequilibrium phase transformations during RIFW are a significant challenge for understanding and predicting their joining behavior and have not been reported in detail. In this work, defect-free AISI 422 steel-AISI 4140 multimaterial pistons were successfully fabricated using the RIFW process. The interfacial microstructure and mechanical properties of dissimilar 422/4140 steel RIFW in the as-welded condition were experimentally studied in detail. The results provide critical baseline information for understanding RIFW mechanisms and guiding subsequent postweld heat treatment (PWHT) practice.

Atomistic Simulation of Temperature-Dependent Interfacial Diffusion between Solid Nickel and Liquid Aluminum

The performance and durability of welded joints are directly influenced by interfacial diffusion between the metals involved, making it essential to investigate the effect of temperature on these processes. The present research examines temperature-dependent diffusion mechanisms at the interface between solid nickel and liquid aluminum using molecular dynamics simulations. Investigations were conducted at 1200, 1300, 1400, and 1500 K to explore the influence of temperature on atomic mobility and interfacial mixing. Radial distribution function analysis revealed a significant increase in the diffusion of nickel atoms into the aluminum phase with increasing temperature, indicating enhanced atomic interactions at the interface. The mean square displacement analysis supported these findings, showing that aluminum atoms were more mobile than nickel atoms at lower temperatures, while nickel atoms exhibited a faster diffusion rate with increasing temperature, surpassing aluminum in mobility. This trend is reflected in the diffusion coefficients, which exhibit a temperature-dependent increase in the diffusion rate of the nickel atoms. These results emphasize the role of temperature in controlling the diffusion dynamics at the solid–liquid interface. The insights gained from this study are critical for optimizing processes, such as dissimilar metal welding, where precise control over interfacial diffusion is essential for achieving the desired material properties and ensuring the structural integrity of nickel–aluminum joints in high-temperature applications.

Effect of heat input on microstructural evolution and impact toughness in dissimilar weld metals between medium Mn and V-microalloyed steel

Effect of heat input on microstructural evolution and impact toughness in dissimilar weld metals between medium Mn and V-microalloyed steel

The Effect of Preheating on the Mechanical Properties of AISI 1037 and AISI 304 Welded Joints Using Shielded Metal Arc Welding.

This study explores the effect of preheating on the toughness of dissimilar welded joints between AISI 1037 and AISI 304 steels, using Shielded Metal Arc Welding (SMAW) and E309-16 electrodes. The innovation of this approach lies in assessing how preheating temperatures influence the mechanical properties of such welds. Preheating temperatures ranged from 150 °C to 300 °C, with impact testing revealing a notable increase in toughness, from 6.01 Joules at 150 °C to 19.57 Joules at 300 °C. Hardness tests indicated a maximum hardness of 313 VHN in the fusion zone and a minimum of 185 VHN in the AISI 304 area. Compared to non-preheated joints, preheating significantly enhanced impact strength and altered the fracture mode from brittle to ductile. Macrostructural and microstructural analyses with optical microscopy and SEM showcased changes in fracture surfaces and microstructural evolution, highlighting the improvement in mechanical properties due to preheating. These findings demonstrate that preheating critically enhances the toughness and overall performance of dissimilar metal welds, making it a valuable technique in industrial applications where enhanced joint toughness is crucial.

Atypical Attack of the Dissimilar Metal Welds of a Water–Water Energetic Reactor Nuclear Power Plant Secondary Circuit: Possible Mechanisms of Failure

ABSTRACTDissimilar metal welds are utilized in the energy industry to connect two materials with different material characteristics. In the case of nuclear power plants, the connected materials tend to be low‐alloyed steel and high‐alloyed material. Despite different material and corrosion properties, under the proper environmental conditions, the used construction materials and weld metals are protected either by a passive layer or by a high‐temperature oxide. Although dissimilar metal welds are used in both primary and secondary circuits, the most frequently documented damage is in the secondary circuit, where, in addition to material heterogeneities, local environmental heterogeneities may form. For dissimilar metal welds in WWER nuclear power plants, a water–water energetic reactor, a subtype of pressure water reactor, we note two main types of attack near the dissimilar fusion boundary: on the carbon steel side or on the high‐alloyed weld metal side (X10CrNiMoN16‐25‐6). The possible causes of the latter “atypical” corrosion attack are debated and can be generalized as a consequence of change of the grain boundary condition.

Performance Optimization of Ti-Steel Laser-Welded Joints Based on Optimized Support Vector Machine and Multi-Objective Salp Swarm Algorithm

<div>The dissimilar welding of titanium to steel enables the integration of the advantageous properties of both metals, facilitating the design of lightweight, corrosion-resistant, and high-strength multifunctional composite structures. However, significant differences in their thermophysical properties pose substantial technical challenges in practical welding scenarios, necessitating careful selection of process parameters to enhance the quality and performance of the weld joint. This article establishes a support vector machine (SVM) model with laser power, welding speed, and laser spot diameter as independent variables, and the maximum residual stress and minimum yield strength of the weld joint as dependent variables. To improve prediction accuracy, the SVM model is optimized using the beluga whale optimization (BWO) algorithm. Taking the established model as the objective function, the multi-objective salp swarm algorithm (MSSA) is employed to optimize the laser welding process parameters for titanium–steel dissimilar metal welding. Simulation experiments validate the efficacy of this optimization approach.</div>

Microstructural features and mechanical properties of in-situ remelting welding of TC4 titanium alloy and T2 copper welded joint by electron beam

Microstructural features and mechanical properties of in-situ remelting welding of TC4 titanium alloy and T2 copper welded joint by electron beam