Investigation of microstructural, dynamic mechanical and high temperature corrosion behaviour of CMT-deposited Nickel Alloy 718 on Stainless Steel 304

Investigation of microstructural, dynamic mechanical and high temperature corrosion behaviour of CMT-deposited Nickel Alloy 718 on Stainless Steel 304 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Short Report Investigation of microstructural, dynamic mechanical and high temperature corrosion behaviour of CMT-deposited Nickel Alloy 718 on Stainless Steel 304 S Gejendhiran, Karpagaraj Anbalagan, R Prithivirajan, R K Nivedhaa, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8526412/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Nickel Alloy 718 (NA718) is hardfaced over Stainless Steel 304 using Cold Metal Transfer process with sinewave weaving. The hardfaced layer exhibited an optimum dilution of 17.3%. Microstructural study depicts the grain transitions from columnar to fine equiaxed. Fine grains and intermetallics are aided to enhance the microhardness upto 66.29% than the substrate. The dynamic mechanical analysis reveals that NA718 offers better damping characteristics. Intermetallics and secondary phases serve as nucleation points for the development of voids and pores. It contributes to the energy dissipation leads to better thermal and dynamic stability. NA718 exhibits lower weight gain (0.0473g) with a smoother corrosion morphology and reduced pit formation, which improves its superior oxidation resistance. NA718 Hardfacing CMT Microstructure High-temperature corrosion DMA Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction Engineering parts such as turbine disks, impellers, heat exchangers, tubes, pressure vessels, rotors of turbochargers, and aero engine blades are operating in aggressive environments like high temperature corrosion, dynamic mechanical environments, and sudden loads[1]. Continuous exposure to these environments diminishes their properties and reduces service life. Hardfacing is an effective surface protection technique, enhances characteristics of the substrate without sacrificing its bulk properties[2]. Cold Metal Transfer (CMT) excels among hardfacing techniques by virtue of its lower heat input, excellent dilution control, spatterless operation, and high deposition rate[3]. Hardface material can be deposited using the arc manipulation strategies, like weaving pattern and stringer bead techniques. Weaving torch motion enhances movement of molten metal, promoting heat transfer, and this restricts secondary arm space growth, grain refinement felicitation, and minimizing substrate dilution[4]. These changes in dilution and microstructural developments will influence the mechanical, properties and dynamic mechanical and corrosion characteristics of the overlay layer. An extensive review of existing literature indicates a distinct lack of studies exploring hardfacing using CMT with weaving techniques. Furthermore, very limited attention has been given to understanding their influence on high-temperature corrosion with different combinations of molten salts and dynamic mechanical characteristics with varying frequency and temperature. This study involves the deposition of NA718 onto SS304 substrate utilizing the CMT method integrated with a sinewave weaving pattern. Post-deposition evaluations includes dilution, microstructural characterization, hardness profiling, and dynamic mechanical and high-temperature corrosion analysis of the hardfaced layers. 2. Materials and experimental approach In this study, NA718 is deposited on austenitic stainless steel 304 (BS SS304) using a Fronius 400i CMT machine, employing sinewave weaving technique using Kawasaki robotic setup. During the deposition process, the parameters are maintained as: welding current = 170 A, voltage = 14.5 A, speed = 15 m/min. The Shielding gas (75%Ar + 25%CO 2 ) is delivered at a flow rate of 15L/min. Carl Zeiss A1 Axiovert optical microscope is used to capture the images for microstructural characterization. After that, microhardness measurements are taken by using Struers Duramin tester with 500N applied load with 30s dwell time. Then, the dynamic mechanical characteristics PerkinElmer 8000 dynamic mechanical analyser with different oscillating frequency levels (1, 10, 50, and 100Hz). During the testing, temperature varies from 30°C to 400°C at a rate of 5°C/minute. High-temperature corrosion test was performed with molten salts (5%V₂O₅+20%NaCl + 75%Na₂SO₄) at 1000°C and corrosion surface morphologies were characterised through Jeol JCM micrographs. 3. Results and Discussions Initially, the NA718 is deposited onto the BS SS304 utilizing the CMT process by employing sinewave weaving with a bead overlap of 30%. It developed the hardfaced layer without any spatters and unwanted material runoffs. And, the NA718 layer produces a dilution of 17.3%. With the bead dimensions of width (33.48 mm), depth of penetration (0.68 mm), and height (3.25 mm)(Fig. 1 a), it agrees with previous results [5]. The OM image of BS SS304 displays the ferrite, austenite grains, and annealing twins (Fig. 1 b). And Fig. 1 c exhibits the Heat Affected Zone (HAZ), Partially Melted Zone (PMZ), InterFace Zone (IFZ) and the Hardfaced Layer (HFL). Thermal susceptibility of HAZ from the IFZ develops the coarser grains. Micro fissuring is a primary concern during the solidification of Ni-alloys, as it causes intergranular liquation[6]. This intergranular liquation inhibits the cohesion of grain boundaries and initiates cracking. Low heat input offered by CMT and the sinewave technique, with overlapping of beads, enhances the transfer of heat. It narrows the HAZ and eliminates intergranular liquation. At the beginning of solidification, the solidification rate (R) is low and the growth rate (G) is more it endorses epitaxial growth, yielding the grains in a columnar structure (Fig. 1 d). As the solidification rate increases, it creates the uneven mixing of liquid and solid phases, and develops the cellular grains. Sinewave weaving uses the lateral movements of arc and reduces the thermal gradient. Due to that, the grains will transform into fine equiaxed grains (Fig. 1 e). Further, the overlapping of beads breaks grain growth, reorients them, and develops finer grains. These fine grains are needed to enhance the overall properties of the coated layer. The distributions of elements are identified from the EDX spectrum (Fig. 2 ). As solidification takes place highly soluble elements like Ni, Cr, and Si are transferred to the dendritic regions (ɣ-phase), and more segregation tendency elements like Nb and Mo are transferred to interdendritic regions. The ɣ-phases (Ni-matrix) and intermetallics are identified as grey and white colours[7]. These elements combine carbon and form laves and intermetallics (NbC). Here, the sinewave weaving increases heat transfer by stirring action and reduces the formation of secondary phases. Furthermore, an increase in heat transfer reduces the formation of secondary arm spacing, yielding finer grains. In addition, previous studies show that it promotes subgrain formations and increases lower-angle grain boundaries [8]. Microhardness of BS SS304 is indicated as 208.9HV 0.5 . And, a fall in hardness is observed in HAZ, which shows 190.3HV 0.5 . Thermal exposure from the IFZ softens and develops the coarser grain, reducing the hardness in HAZ. The intermixing of elements promotes the hardness in IFZ. Then the increasing trend is observed in the overlay layer it reaching a maximum hardness of 348.7HV 0.5 [9]. The hardfaced layer elevated the hardness by 66.29% of the base substrate. Development of fine grains, intermetallics, and strengthening elements particularly Mo and Nb resists the indenter impingement and enhances the hardness. The dynamic mechanical analysis results shows that BS SS304 has a storage modulus (E′) ranging from 1.53 × 10 10 MPa to 1.60 × 10 10 MPa across frequencies of 1-100Hz, reflecting consistent elastic behaviour under dynamic loading conditions. In comparison, the NA718 coating exhibits slightly higher E′ values, between 2.07 × 10 10 MPa to 2.10 × 10 10 MPa. The storage modulus shows slight variations with changing frequency aligning with previous findings. An increase in frequency and temperature enhances molecular movements, it slightly lowers stiffness and storage modulus[10]. For BS SS304, the loss modulus (E″) at 1Hz is 1.83× 10 9 MPa and 2.33× 10 9 MPa at 100Hz. Considering NA718, it shows that E″ at 1Hz is 3.35× 10 9 MPa and 5.91× 10 9 MPa at 100Hz. In the same way, the Tan Delta increased from 0.0.95 to 0.173 across the frequency ranges (1Hz to 100Hz) for SS304. And, Tan Delta for NA718 layer exhibited a significant increase from 0.144 at 1Hz to 0.373 at 100Hz (Fig. 3 a,b&c). These results exhibited that the increase in temperature and frequency promotes the thermal softening. It consistently promotes the energy transfer in terms of heat. The substrate and overlay layer possesses strong intergranular interactions due to the inherent characteristics, and since the applied energy is lower than grain interaction force, the storage modulus improves more substantially than loss modulus. The fractured morphology of the samples displayed that both samples hold pores and voids (Fig. 3 d&e). But the NA718 layer holds more cluster pores helps to enhance energy dissipation. The presence of intermetallics and precipitates contributes to internal friction (Fig. 3 f). And, it acts as a nucleation point of the development of voids and pores [11]. The alloying elements Mo, Nb and Ti forms tiny precipitates and reduce grain boundary movement, it slows down dislocation motion. In terms of microstructure, the overlay layer changes from a columnar to equiaxed grain form. This transformation, along with strengthening effect of alloying elements gives NA718 better resistance to dynamic loading and improves its thermal stability. Findings of high-temperature corrosion display that the minimum weight gain of the NA718 layer is 0.0473 grams and for BS SS304 is 0.5036 grams (Fig. 4 a). On the other hand, the maximum weight gains are recorded at 0.0544 and 0.5407 grams. The formation of acidic fluxes and salt melting influences the increase in weight gain at earlier stages[12]. After the development of a chromium layer protects the surfaces from corrosion attacks. Later, the compounds of vanadium and sulfides increase the oxygen activity by depleting the protective layer. Corrosion morphology (Fig. 4 b&c) shows the BS SS304 holding larger-sized pits and lengthy cracks. At 1000°C, rapid formation of oxides triggers spallation, culminating in ridge-shaped and cauliflower-like structures. 4. Conclusion As evidenced by the above results, the following findings are concluded: The NA718 hardfaced layer achieved an optimum dilution of 17.3% attributed to sinewave weaving, where the oscillating arc and overlapping beads effectively transferred partial heat to the previous layer promoting uniform dilution. Coarser grains were formed in HAZ due to the thermal susceptibility, while the overlay layer exhibited dendritic grains formed through directional solidification, transitioning from columnar to equiaxed morphology. The strong segregation tendency of Nb and Mo interdendritic regions felicitate the formation of Laves phase and intermetallic compounds, significantly improving microhardness upto 66.29% compared to the substrate. DMA results revealed that increasing frequency and temperature slightly reduced storage modulus while enhancing the loss modulus and damping capacity. Presence of intermetallic and secondary phases in NA718 acted as energy dissipation sites, improving its vibration resistance and thermal stability. At 1000C, NA718 limits weight gain to 0.0544 g offering better oxidation resistance. The spallation of layers shows pits, cracks and ridge shaped cauliflower like corrosion structures. Declarations Conflict of Interest Authors declare that they have no Conflict of Interest Author Contribution S Gejendhiran - Investigation, Written Full Manuscript, Reviewed the manuscriptKarpagaraj Anbalagan - Methodology, Reviewed the manuscriptR Prithivirajan - Partial Investigation, Reviewed the manuscriptR K Nivedhaa - Reviewed the manuscriptRavikumar Jayabal - Partial Investigation, Reviewed the manuscript References C.-M.Lin, T.-L.Su, K.-Y.Wu,Effects of parameter optimization on microstructure and properties of GTAW clad welding on AISI 304L stainless steel using Inconel 52M,Int.J. Adv.Manuf.Technol.79(2015)2057–2066. 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M.Naghiyan Fesharaki, R.Shoja-Razavi, H.A.Mansouri, H.Jamali,Evaluation of the hot corrosion behavior of Inconel 625 coatings on the Inconel 738 substrate by laser and TIG cladding techniques,Opt.Laser Technol.111(2019)744–753. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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1","display":"","copyAsset":false,"role":"figure","size":1467050,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(a) Sectional profile (b) SS304 (c) Interface zone (d \u0026amp; e) Hardfaced layer\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8526412/v1/16c50a62f6f06cae6e3eec34.png"},{"id":100597221,"identity":"dcad0f61-7aae-406e-9b70-4a76fafe53d7","added_by":"auto","created_at":"2026-01-19 14:14:52","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":576577,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEDX Spectrum on hardfaced layer and Laves 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4","display":"","copyAsset":false,"role":"figure","size":413514,"visible":true,"origin":"","legend":"\u003cp\u003e(a) High temperature corrosion result (b\u0026amp;c) Corroded surface morphology\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8526412/v1/9139438db8c6e77be7213055.png"},{"id":101752193,"identity":"523d612f-6591-49b5-a8ff-d125c49bcde3","added_by":"auto","created_at":"2026-02-03 10:25:59","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3203737,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8526412/v1/00c21f0f-3ce9-441c-b006-bcf7a7f4573b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Investigation of microstructural, dynamic mechanical and high temperature corrosion behaviour of CMT-deposited Nickel Alloy 718 on Stainless Steel 304","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eEngineering parts such as turbine disks, impellers, heat exchangers, tubes, pressure vessels, rotors of turbochargers, and aero engine blades are operating in aggressive environments like high temperature corrosion, dynamic mechanical environments, and sudden loads[1]. Continuous exposure to these environments diminishes their properties and reduces service life. Hardfacing is an effective surface protection technique, enhances characteristics of the substrate without sacrificing its bulk properties[2]. Cold Metal Transfer (CMT) excels among hardfacing techniques by virtue of its lower heat input, excellent dilution control, spatterless operation, and high deposition rate[3]. Hardface material can be deposited using the arc manipulation strategies, like weaving pattern and stringer bead techniques. Weaving torch motion enhances movement of molten metal, promoting heat transfer, and this restricts secondary arm space growth, grain refinement felicitation, and minimizing substrate dilution[4]. These changes in dilution and microstructural developments will influence the mechanical, properties and dynamic mechanical and corrosion characteristics of the overlay layer. An extensive review of existing literature indicates a distinct lack of studies exploring hardfacing using CMT with weaving techniques. Furthermore, very limited attention has been given to understanding their influence on high-temperature corrosion with different combinations of molten salts and dynamic mechanical characteristics with varying frequency and temperature. This study involves the deposition of NA718 onto SS304 substrate utilizing the CMT method integrated with a sinewave weaving pattern. Post-deposition evaluations includes dilution, microstructural characterization, hardness profiling, and dynamic mechanical and high-temperature corrosion analysis of the hardfaced layers.\u003c/p\u003e"},{"header":"2. Materials and experimental approach","content":"\u003cp\u003eIn this study, NA718 is deposited on austenitic stainless steel 304 (BS SS304) using a Fronius 400i CMT machine, employing sinewave weaving technique using Kawasaki robotic setup. During the deposition process, the parameters are maintained as: welding current\u0026thinsp;=\u0026thinsp;170 A, voltage\u0026thinsp;=\u0026thinsp;14.5 A, speed\u0026thinsp;=\u0026thinsp;15 m/min. The Shielding gas (75%Ar\u0026thinsp;+\u0026thinsp;25%CO\u003csub\u003e2\u003c/sub\u003e) is delivered at a flow rate of 15L/min. Carl Zeiss A1 Axiovert optical microscope is used to capture the images for microstructural characterization. After that, microhardness measurements are taken by using Struers Duramin tester with 500N applied load with 30s dwell time. Then, the dynamic mechanical characteristics PerkinElmer 8000 dynamic mechanical analyser with different oscillating frequency levels (1, 10, 50, and 100Hz). During the testing, temperature varies from 30\u0026deg;C to 400\u0026deg;C at a rate of 5\u0026deg;C/minute. High-temperature corrosion test was performed with molten salts (5%V₂O₅+20%NaCl\u0026thinsp;+\u0026thinsp;75%Na₂SO₄) at 1000\u0026deg;C and corrosion surface morphologies were characterised through Jeol JCM micrographs.\u003c/p\u003e"},{"header":"3. Results and Discussions","content":"\u003cp\u003eInitially, the NA718 is deposited onto the BS SS304 utilizing the CMT process by employing sinewave weaving with a bead overlap of 30%. It developed the hardfaced layer without any spatters and unwanted material runoffs. And, the NA718 layer produces a dilution of 17.3%. With the bead dimensions of width (33.48 mm), depth of penetration (0.68 mm), and height (3.25 mm)(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea), it agrees with previous results [5].\u003c/p\u003e \u003cp\u003eThe OM image of BS SS304 displays the ferrite, austenite grains, and annealing twins (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). And Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec exhibits the Heat Affected Zone (HAZ), Partially Melted Zone (PMZ), InterFace Zone (IFZ) and the Hardfaced Layer (HFL). Thermal susceptibility of HAZ from the IFZ develops the coarser grains. Micro fissuring is a primary concern during the solidification of Ni-alloys, as it causes intergranular liquation[6]. This intergranular liquation inhibits the cohesion of grain boundaries and initiates cracking. Low heat input offered by CMT and the sinewave technique, with overlapping of beads, enhances the transfer of heat. It narrows the HAZ and eliminates intergranular liquation. At the beginning of solidification, the solidification rate (R) is low and the growth rate (G) is more it endorses epitaxial growth, yielding the grains in a columnar structure (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed). As the solidification rate increases, it creates the uneven mixing of liquid and solid phases, and develops the cellular grains. Sinewave weaving uses the lateral movements of arc and reduces the thermal gradient. Due to that, the grains will transform into fine equiaxed grains (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee). Further, the overlapping of beads breaks grain growth, reorients them, and develops finer grains. These fine grains are needed to enhance the overall properties of the coated layer.\u003c/p\u003e\u003cp\u003eThe distributions of elements are identified from the EDX spectrum (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). As solidification takes place highly soluble elements like Ni, Cr, and Si are transferred to the dendritic regions (ɣ-phase), and more segregation tendency elements like Nb and Mo are transferred to interdendritic regions. The ɣ-phases (Ni-matrix) and intermetallics are identified as grey and white colours[7]. These elements combine carbon and form laves and intermetallics (NbC). Here, the sinewave weaving increases heat transfer by stirring action and reduces the formation of secondary phases. Furthermore, an increase in heat transfer reduces the formation of secondary arm spacing, yielding finer grains. In addition, previous studies show that it promotes subgrain formations and increases lower-angle grain boundaries [8].\u003c/p\u003e \u003cp\u003eMicrohardness of BS SS304 is indicated as 208.9HV\u003csub\u003e0.5\u003c/sub\u003e. And, a fall in hardness is observed in HAZ, which shows 190.3HV\u003csub\u003e0.5\u003c/sub\u003e. Thermal exposure from the IFZ softens and develops the coarser grain, reducing the hardness in HAZ. The intermixing of elements promotes the hardness in IFZ. Then the increasing trend is observed in the overlay layer it reaching a maximum hardness of 348.7HV\u003csub\u003e0.5\u003c/sub\u003e[9]. The hardfaced layer elevated the hardness by 66.29% of the base substrate. Development of fine grains, intermetallics, and strengthening elements particularly Mo and Nb resists the indenter impingement and enhances the hardness.\u003c/p\u003e \u003cp\u003eThe dynamic mechanical analysis results shows that BS SS304 has a storage modulus (E\u0026prime;) ranging from 1.53 \u0026times; 10\u003csup\u003e10\u003c/sup\u003e MPa to 1.60 \u0026times; 10\u003csup\u003e10\u003c/sup\u003e MPa across frequencies of 1-100Hz, reflecting consistent elastic behaviour under dynamic loading conditions. In comparison, the NA718 coating exhibits slightly higher E\u0026prime; values, between 2.07 \u0026times; 10\u003csup\u003e10\u003c/sup\u003e MPa to 2.10 \u0026times; 10\u003csup\u003e10\u003c/sup\u003e MPa. The storage modulus shows slight variations with changing frequency aligning with previous findings. An increase in frequency and temperature enhances molecular movements, it slightly lowers stiffness and storage modulus[10].\u003c/p\u003e \u003cp\u003eFor BS SS304, the loss modulus (E\u0026Prime;) at 1Hz is 1.83\u0026times; 10\u003csup\u003e9\u003c/sup\u003e MPa and 2.33\u0026times; 10\u003csup\u003e9\u003c/sup\u003e MPa at 100Hz. Considering NA718, it shows that E\u0026Prime; at 1Hz is 3.35\u0026times; 10\u003csup\u003e9\u003c/sup\u003e MPa and 5.91\u0026times; 10\u003csup\u003e9\u003c/sup\u003e MPa at 100Hz. In the same way, the Tan Delta increased from 0.0.95 to 0.173 across the frequency ranges (1Hz to 100Hz) for SS304. And, Tan Delta for NA718 layer exhibited a significant increase from 0.144 at 1Hz to 0.373 at 100Hz (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea,b\u0026amp;c). These results exhibited that the increase in temperature and frequency promotes the thermal softening. It consistently promotes the energy transfer in terms of heat. The substrate and overlay layer possesses strong intergranular interactions due to the inherent characteristics, and since the applied energy is lower than grain interaction force, the storage modulus improves more substantially than loss modulus. The fractured morphology of the samples displayed that both samples hold pores and voids (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed\u0026amp;e). But the NA718 layer holds more cluster pores helps to enhance energy dissipation. The presence of intermetallics and precipitates contributes to internal friction (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef). And, it acts as a nucleation point of the development of voids and pores [11]. The alloying elements Mo, Nb and Ti forms tiny precipitates and reduce grain boundary movement, it slows down dislocation motion. In terms of microstructure, the overlay layer changes from a columnar to equiaxed grain form. This transformation, along with strengthening effect of alloying elements gives NA718 better resistance to dynamic loading and improves its thermal stability.\u003c/p\u003e\u003cp\u003eFindings of high-temperature corrosion display that the minimum weight gain of the NA718 layer is 0.0473 grams and for BS SS304 is 0.5036 grams (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). On the other hand, the maximum weight gains are recorded at 0.0544 and 0.5407 grams. The formation of acidic fluxes and salt melting influences the increase in weight gain at earlier stages[12]. After the development of a chromium layer protects the surfaces from corrosion attacks. Later, the compounds of vanadium and sulfides increase the oxygen activity by depleting the protective layer. Corrosion morphology (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb\u0026amp;c) shows the BS SS304 holding larger-sized pits and lengthy cracks. At 1000\u0026deg;C, rapid formation of oxides triggers spallation, culminating in ridge-shaped and cauliflower-like structures.\u003c/p\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eAs evidenced by the above results, the following findings are concluded:\u003c/p\u003e \u003cp\u003eThe NA718 hardfaced layer achieved an optimum dilution of 17.3% attributed to sinewave weaving, where the oscillating arc and overlapping beads effectively transferred partial heat to the previous layer promoting uniform dilution. Coarser grains were formed in HAZ due to the thermal susceptibility, while the overlay layer exhibited dendritic grains formed through directional solidification, transitioning from columnar to equiaxed morphology. The strong segregation tendency of Nb and Mo interdendritic regions felicitate the formation of Laves phase and intermetallic compounds, significantly improving microhardness upto 66.29% compared to the substrate. DMA results revealed that increasing frequency and temperature slightly reduced storage modulus while enhancing the loss modulus and damping capacity. Presence of intermetallic and secondary phases in NA718 acted as energy dissipation sites, improving its vibration resistance and thermal stability. At 1000C, NA718 limits weight gain to 0.0544 g offering better oxidation resistance. The spallation of layers shows pits, cracks and ridge shaped cauliflower like corrosion structures.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eConflict of Interest\u003c/h2\u003e \u003cp\u003eAuthors declare that they have no Conflict of Interest\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eS Gejendhiran - Investigation, Written Full Manuscript, Reviewed the manuscriptKarpagaraj Anbalagan - Methodology, Reviewed the manuscriptR Prithivirajan - Partial Investigation, Reviewed the manuscriptR K Nivedhaa - Reviewed the manuscriptRavikumar Jayabal - Partial Investigation, Reviewed the manuscript\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eC.-M.Lin, T.-L.Su, K.-Y.Wu,Effects of parameter optimization on microstructure and properties of GTAW clad welding on AISI 304L stainless steel using Inconel 52M,Int.J. Adv.Manuf.Technol.79(2015)2057\u0026ndash;2066.\u003c/li\u003e\n\u003cli\u003eY.Ning, Z.Qiu, B.Wu, Z.Pan, H.Li,Hardfacing of metals: A review of consumables, properties and strengthening processes, J.Mater.Res.Technol.36(2025)6330\u0026ndash;6349.\u003c/li\u003e\n\u003cli\u003eJ.Tapiola, J.Tuominen, J.Vihinen, P.Vuoristo,Sliding wear behavior of cold metal transfer cladded Stellite 12 hardfacings on martensitic stainless steel,Weld.World67(2023)573\u0026ndash;584.\u003c/li\u003e\n\u003cli\u003eM.Lara, V.V.D\u0026iacute;az, M.Camus, T.V.Da Cunha,Effect of transverse arc oscillation on morphology, dilution and microstructural aspects of weld beads produced with short-circuiting transfer in GMAW,J.Braz.Soc.Mech.Sci.Eng.42(2020). \u003c/li\u003e\n\u003cli\u003eD.T.Sarathchandra, M.J.Davidson, G.Visvanathan,Parameters effect on SS304 beads deposited by wire arc additive manufacturing,Mater.Manuf.Process.35(2020)852\u0026ndash;858. \u003c/li\u003e\n\u003cli\u003eA.Evangeline, P.Sathiya,Dissimilar Cladding of Ni\u0026ndash;Cr\u0026ndash;Mo Superalloy over 316L Austenitic Stainless Steel:Morphologies and Mechanical Properties,Met.Mater.Int.27 (2021)1155\u0026ndash;1172.\u003c/li\u003e\n\u003cli\u003eH.Kim, W.Cong, H.-C.Zhang, Z.Liu,Laser Engineered Net Shaping of Nickel-Based Superalloy Inconel 718 Powders onto AISI 4140 Alloy Steel Substrates:Interface Bond and Fracture Failure Mechanism,Materials10(2017)341. \u003c/li\u003e\n\u003cli\u003eS.Gejendhiran, A.Karpagaraj, D.V.Kumar, R.Dhanusuraman, N.Annamalai,Experimental investigations on Inconel 718 hard-faced layer deposited over SS304 using cold metal transfer,Surf.Coat.Technol.468(2023)129739. \u003c/li\u003e\n\u003cli\u003eN.A.Kistler, A.R.Nassar, E.W.Reutzel, D.J.Corbin, A.M. Beese,Effect of directed energy deposition processing parameters on laser deposited Inconel\u0026reg; 718:Microstructure, fusion zone morphology, and hardness,J.Laser Appl.29(2017). \u003c/li\u003e\n\u003cli\u003eK.A.Khor, C.T.Chia, Y.W.Gu, Dynamic mechanical properties of plasma sprayed Ni-based alloys,Mater.Sci.Eng.A 279(2000)166\u0026ndash;171. \u003c/li\u003e\n\u003cli\u003eP.Sun, Q.Wang, J.Feng, P.Ji, J.Zhang, F.Yin,Effect of Nb on the Damping Property and Pseudoelasticity of a Porous Ni-Ti Shape Memory Alloy,Materials 16(2023)5057. \u003c/li\u003e\n\u003cli\u003eM.Naghiyan Fesharaki, R.Shoja-Razavi, H.A.Mansouri, H.Jamali,Evaluation of the hot corrosion behavior of Inconel 625 coatings on the Inconel 738 substrate by laser and TIG cladding techniques,Opt.Laser Technol.111(2019)744\u0026ndash;753. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"NA718, Hardfacing, CMT, Microstructure, High-temperature corrosion, DMA","lastPublishedDoi":"10.21203/rs.3.rs-8526412/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8526412/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eNickel Alloy 718 (NA718) is hardfaced over Stainless Steel 304 using Cold Metal Transfer process with sinewave weaving. The hardfaced layer exhibited an optimum dilution of 17.3%. Microstructural study depicts the grain transitions from columnar to fine equiaxed. Fine grains and intermetallics are aided to enhance the microhardness upto 66.29% than the substrate. The dynamic mechanical analysis reveals that NA718 offers better damping characteristics. Intermetallics and secondary phases serve as nucleation points for the development of voids and pores. It contributes to the energy dissipation leads to better thermal and dynamic stability. NA718 exhibits lower weight gain (0.0473g) with a smoother corrosion morphology and reduced pit formation, which improves its superior oxidation resistance.\u003c/p\u003e","manuscriptTitle":"Investigation of microstructural, dynamic mechanical and high temperature corrosion behaviour of CMT-deposited Nickel Alloy 718 on Stainless Steel 304","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-19 08:30:02","doi":"10.21203/rs.3.rs-8526412/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c880566a-0967-40dd-a068-9de806e89aa7","owner":[],"postedDate":"January 19th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-01-31T00:53:23+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-19 08:30:02","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8526412","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8526412","identity":"rs-8526412","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}