Comparative analysis of microstructural and nanomechanical characteristics of MIG and TIG-MIG hybrid welded inconel 718 and AISI 316 with steel and inconel fillers
Restricted accessResearch articleFirst published online November, 2025
Comparative analysis of microstructural and nanomechanical characteristics of MIG and TIG-MIG hybrid welded inconel 718 and AISI 316 with steel and inconel fillers
The joining of Austenitic Stainless Steel (AISI 316) and Inconel (IN718) was carried out using Metal Inert Gas (MIG) welding and hybrid TIG-MIG welding with Inconel (IN625) and steel fillers. The resulting weldments were examined for their microstructural and compositional characteristics, elastic modulus, and nano-hardness using optical microscopy, X-ray diffraction, and nanoindentation techniques. The results indicated that the base metal IN718 exhibited higher hardness and elastic modulus compared to AISI 316. Additionally, the formation of the δ-Ni3Nb phase was observed in both MIG and hybrid welding processes using IN625 filler, along with austenitic matrices of Fe and Ni. When steel filler was used, it led to the development of a finer cellular, columnar, and equiaxed dendritic microstructure compared to the IN625 filler. The highest hardness in the heat-affected zone (HAZ) of IN718 was observed in hybrid welding with the steel filler, which was 7% and 5% higher compared to MIG welding with IN625 and steel fillers, respectively. Moreover, the maximum hardness in the fusion zone (FZ) of 4.55 GPa was achieved in MIG welding with the steel filler, which was 36% and 69% higher compared to hybrid welding with steel and IN625 fillers, respectively. The hardness varied between 2.74 GPa and 3.62 GPa in the HAZ of AISI 316 for MIG welding with steel and IN625 fillers, respectively. The elastic modulus was found to be 213 GPa in MIG welding with IN625 filler and 214 GPa in hybrid welding with steel filler. Pile-up behavior was observed around the nanoindents for all weldments obtained in both MIG and hybrid welding using steel and IN625 fillers.
ChenHCPinkertonAJLiL. Fibre laser welding of dissimilar alloys of Ti-6Al-4V and inconel 718 for aerospace applications. Int J Adv Manuf Technol2011; 52: 977–987.
2.
DakGSirohiSPandeyC. Study on microstructure and mechanical behavior relationship for laser-welded dissimilar joint of P92 martensitic and 304L austenitic steel. Int J Press Vessel Pip2022; 196: 104629.
3.
KanemaruSSasakiTSatoT, et al.Study for TIG–MIG hybrid welding process. Weld World2014; 58: 11–18.
4.
ZhouY-BFangD-SLiuL-M. Root welding of V-groove thick plate without backing plate by MAG-TIG double-arc welding. Int J Precis Eng Manuf2017; 18: 623–628.
5.
SamuelCAkinwaleSMadusheleN,et al.Comparative study between TIG-MIG hybrid, TIG and MIG welding of 1008 steel joints for enhanced structural integrity. Sci African2022; 17: e01329.
6.
SchneiderCFLisboaCPSilvaRDA, et al.Optimizing the parameters of TIG-MIG / MAG hybrid welding on the geometry of bead welding using the taguchi method. J Manuf Mater Process2017; 1: 14.
7.
KhanSAliZRehmanK,et al.Mechanical and microstructural characterization of diffusion-bonded copper-nickel joint interface. Adv Mater Res2024; 1179: 147–155.
8.
BaiYLuQRenX, et al.Study of inconel 718 welded by bead-on-plate Laser welding under high-frequency micro-vibration condition. Metals (Basel)2019; 9: 1335.
9.
KimJSParkYILLeeHW. Effects of heat input on the pitting resistance of inconel 625 welds by overlay welding. Met Mater Int2015; 21: 350–355.
10.
KhanSJunaidMShehbazT. Evaluations of nanomechanical and indentation creep of diffusion-bonded aluminum and austenitic stainless steel joint interface. Proc Inst Mech Eng Part L J Mater Des Appl2024. 10.1177/14644207241290447
11.
KhanSJunaidMShehbazT,et al.Influence of Cu interlayer on the interfacial strengthening of the diffusion-bonded SS-304L/IN718. Mater Lett2024; 358: 135829.
12.
DökmeFKulekciMEsmeU. Microstructural and mechanical characterization of dissimilar metal welding of Inconel 625 and AISI 316L. Metals (Basel)2018; 8: 797. 10.3390/met8100797
13.
RamkumarTSelvakumarMNarayanasamyP, et al.Studies on the structural property, mechanical relationships and corrosion behaviour of inconel 718 and SS 316L dissimilar joints by TIG welding without using activated flux studies on the structural property, mechanical relationships and corrosion beha. J Manuf Process2022; 30: 290–298.
14.
KimJJPhamTHKimSE. Instrumented indentation testing and FE analysis for investigation of mechanical properties in structural steel weld zone. Int J Mech Sci2015; 103: 265–274.
15.
KhanSKhadijaKJunaidM. Investigation of the influence of bonding parameters on the homogenous diffusion bonding of copper. Mater Sci Forum2024; 1132: 63–70.
16.
KulekciMKEsmeUKahramanF,et al.Advanced hybrid welding and manufacturing technologies. Mater Test2016; 58: 362–370. doi:10.3139/120.110858
17.
YelamasettiBAdithyaGSRamadeviRS, et al.Metallurgical, mechanical and corrosion behaviour of pulsed and constant current TIG dissimilar welds of AISI 430 and inconel 718. J Mater Res Technol2023; 24: 6652–6664.
18.
RamkumarKDMithileshPVarunD, et al.Characterization of microstructure and mechanical properties of inconel 625 and AISI 304 dissimilar weldments. ISIJ Int2014; 54: 900–908.
19.
NaffakhHShamanianMAshrafizadehF. Dissimilar welding of AISI 310 austenitic stainless steel to nickel-based alloy inconel 657. J Mater Process Technol2008; 9: 3628–3639. 10.1016/j.jmatprotec.2008.08.019
20.
Devendranath RamkumarKPatelSDSri PraveenS, et al.Influence of filler metals and welding techniques on the structure – property relationships of inconel 718 and AISI 316L dissimilar weldments. Mater Des2014; 62: 175–188.
21.
NaffakhHShamanianMAshrafizadehF. Microstructural evolutions in dissimilar welds between AISI 310 austenitic stainless steel and inconel 657. J Mater Sci2010; 45: 2564–2573.
22.
NaffakhHShamanianMAshrafizadehF. Dissimilar welding of AISI 310 austenitic stainless steel to nickel-based alloy inconel 657. J Mater Process Technol2009; 209: 3628–3639.
23.
SongYHuangXGaoZ, et al.Nanoindentation creep behavior of RPV’s weld joint at room temperature. Mech Time-Dependent Mater2020; 24: 253–263.
24.
HuJZhangYSunW, et al.Nanoindentation-induced pile-up in the residual impression of crystalline Cu with different grain size. Crystals2018; 8: 9. 10.3390/cryst8010009
25.
KværndrupFBEngelbrektCKücükyildizC, et al.Area determination with pile-up and sink-in in nanoindentation of oxygen containing titanium. 2022; 30. 10.1016/j.mtcomm.2022.103218
26.
KhanSJunaidMShehbazT, et al.Interfacial microstructure and mechanical properties in diffusion bonded inconel 718 to austenitic stainless-steel joints. Proc Inst Mech Eng Part L J Mater Des Appl2024: 14644207241269012. 10.1177/14644207241269012
27.
NguyenNVPhamTHKimSE. Microstructure and strain rate sensitivity behavior of SM490 structural steel weld zone investigated using indentation. Constr Build Mater2019; 206: 410–418.
28.
PhamTHKimJJKimSE. Estimation of microstructural compositions in the weld zone of structural steel using nanoindentation. J Constr Steel Res2014; 99: 121–128.
29.
PhamT-HKimS-E. Characteristics of microstructural phases relevant to the mechanical properties in structural steel weld zone studied by using indentation. Constr Build Mater2017; 155: 176–186.
30.
KhanSJunaidMShehbazT, et al.Nanoindentation creep behavior of vacuum diffusion-bonded stainless steel and inconel 718 joints using a Cu interlayer. Proc Inst Mech Eng Part C J Mech Eng Sci2024: 09544062241285195. 10.1177/09544062241285195
31.
SirohiSPandeySMŚwierczyńskaA, et al.Microstructure and mechanical properties of combined GTAW and SMAW dissimilar welded joints between Inconel 718 and 304L austenitic stainless steel. Metals (Basel)2023; 13. 10.3390/met13010014
32.
KulkarniADwivediDKVasudevanM. Microstructure and mechanical properties of A-TIG welded AISI 316L SS-alloy 800 dissimilar metal joint. Mater Sci Eng A2020: 139685. 10.1016/j.msea.2020.139685
33.
KnorovskyGACieslakMJHeadleyTJ, et al.INCONEL 718: a solidification diagram. Metall Trans A1989; 20: 2149–2158.
34.
ManikandanSGKSivakumarDPrasad RaoK,et al.Laves phase in alloy 718 fusion zone — microscopic and calorimetric studies. Mater Charact2015; 100: 192–206.
35.
SahuAKBagS. Probe pulse conditions and solidification parameters for the dissimilar welding of inconel 718 and AISI 316L stainless steel. Metall Mater Trans A Phys Metall Mater Sci2020; 51: 2192–2208.
36.
KhanSKhadija, JunaidM, et al. Evaluation of nano indentation behavior of TIG, MIG and diffusion bonded inconel 718 and austenitic stainless steel 316L joint interface. Mater Lett2024: 136952. 10.1016/j.matlet.2024.136952
37.
TandonVThombreMAPatilAP, et al.Effect of heat input on the microstructural, mechanical, and corrosion properties of dissimilar weldment of conventional austenitic stainless steel and low - nickel stainless steel. Metallogr Microstruct Anal2020; 9: 668–677.
38.
GopalsamyCKuttalamKC. Investigation on un-peened and laser shock peened dissimilar weldments of Inconel 600 and AISI 316L fabricated using activated-TIG welding technique. Mater Lett2018. 10.1016/j.jmapro.2018.09.004
39.
Ullah KhanNRajputSKGuptaV, et al.To study mechanical properties and microstructures of MIG welded high strength low alloy steel. Mater Today Proc2019; 18: 2550–2555.
40.
M. Characterization, Microstructural and Mechanical Characterization, 2018. 10.3390/met8100797
41.
RamkumarKDPatelSDPraveenSS, et al.Influence of filler metals and welding techniques on the structure – property relationships of inconel 718 and AISI 316L dissimilar weldments. J Mater2014; 62: 175–188.
42.
ElmustafaAAStoneDS. Nanoindentation and the indentation size effect: kinetics of deformation and strain gradient plasticity. J Mech Phys Solids2003; 51: 357–381.
43.
BoumerzougZDerfoufCBaudinT. Effect of welding on microstructure and mechanical properties of an industrial low carbon steel. Engineering2010; 02: 502–506.
44.
LeeC-HShinH-SParkK-T. Evaluation of high strength TMCP steel weld for use in cold regions. J Constr Steel Res2012; 74: 134–139.
45.
YangJLiSZhangM, et al. Welding Process and Welding Consumable of Generation III Nuclear Island Main Equipment. 2017. 10.1007/978-981-10-2317-0_42
46.
LuHBWangBMaJ, et al.Measurement of creep compliance of solid polymers by nanoindentation. Mech Time-Dependent Mater2003; 7: 189–207.
