Microstructures and mechanical behavior of the bimetallic additively-manufactured structure (BAMS) of austenitic stainless steel and Inconel 625

doi:10.1016/j.jmst.2020.10.001

Abstract

Abstract:

Bimetallic additively manufactured structures (BAMSs) can replace traditionally-fabricated functionally-graded-components through fusion welding processes and can eliminate locally-deteriorated mechanical properties arising from post-processing. The present work fabricates a BAMS by sequentially depositing the austenitic stainless-steel and Inconel625 using a gas-metal-arc-welding (GMAW)-based wire + arc additive manufacturing (WAAM) system. Elemental mapping shows a smooth compositional transition at the interface without any segregation. Both materials being the face-center-cubic (FCC) austenite, the electron backscattered diffraction (EBSD) analysis of the interface shows the smooth and cross-interface-crystallographic growth of long-elongated grains in the <001> direction. The hardness values were within the range of 220-240 HV for both materials without a large deviation at the interface. Due to the controlled thermal history, mechanical testing yielded a consistent result with the ultimate tensile strength and elongation of 600 MPa and 40 %, respectively, with the failure location on the stainless-steel side. This study demonstrates that WAAM has the potential to fabricate BAMS with controlled properties.

Key words: WAAM, Additive manufacturing, BAMS, Functionally-graded structures, Microstructures, Mechanical properties

Md. R.U. Ahsan, Xuesong Fan, Gi-Jeong Seo, Changwook Ji, Mark Noakes, Andrzej Nycz, Peter K. Liaw, Duck Bong Kim. Microstructures and mechanical behavior of the bimetallic additively-manufactured structure (BAMS) of austenitic stainless steel and Inconel 625[J]. J. Mater. Sci. Technol., 2021, 74: 176-188.

Figures/Tables 15

Table 1 Chemical composition [weight percent (wt.%)] of SS316 L and In625 consumable wires.

	%C	%Mn	%Si	%S	%P	%Fe	%Cr	%Ni	%Mo	%Nb + Ta	%Cu
SS316 L	0.02	2.1	0.81	0.01	0.02	63.7	18.9	11.8	2.2	-	0.23
In625	0.02	0.1	0.14	0.001	0.005	0.4	21.7	64	8.5	3.8	0.23

Fig. 1. (a) Single beads of SS316 L and In625, (b) Cross sections of single beads with measurements.

Fig. 2. (a) Schematic of the tool-path of deposition, (b) the fabricated BAMS of SS316 L and In625, (c) tensile-test specimens, and (d) dimensions of the tensile-test specimens.

Table 2 Deposition parameters of the BAMS with SS316 L and In625.

	Variables	Unit	SS316 L	In625
Deposition parameters	Welding process	-	CMT
	Ampere	A	200	148
	Voltage	V	13.1	14.5
	Contact tip to work distance (CTWD)	mm	15
	Moving speed	mm/min	600
	Torching angle	Degree	90
	Travel angle	Degree	90
	Layer thickness	mm	3
	x and y offset	mm	3.5
	Bead overlap	%	50
Consumables	Feed rate	m/min.	6.5
Consumables	Diameter	mm	1.2
Substrate and environment	Shielding gas type	-	90 vol.-% Ar +10 vol.-% CO₂	100 vol.-% Ar
	Initial bed temperature	°C	25
	Substrate	-	Low-carbon steel
	Substrate thickness	mm	25
	Shielding gas flow rate	l/min.	20
	Intermediate temperature	°C	200

Fig. 3. (a, b) SEM micrograph of the SS316 L side and (c) higher magnification back-scattered images of the microstructure with elemental mapping results performed on the δ ferrites dendrites.

Fig. 4. Backscattered electron micrograph on the SS316 L side (a) at the 1 st layer on top of the substrate, (b) at the 10th layer, and (c) at the 11th layer.

Fig. 5. EBSD-analysis results on the SS316 L side (a) grain map, (b) IPF-Z color map in the build direction, and (c) pole figure of the map.

Fig. 6. (a, b) SEM-EDX micrograph of the In625 side showing the SSB, SSGB, and MGB and (c) higher magnification microstructure showing laves phases on the SSGBs and elemental mapping data.

Fig. 7. Backscattered electron micrograph on the In625 side (a) at the 1st layer on top of the SS316 L deposit (12th layer), (b) at the 2nd layer (13th layer), (c) at the last layer, (d) graphical representation of the count of laves phase in different layers.

Fig. 8. EBSD analysis results on In625 side (a) grain map and (b) schematic explaining the coarse and fine grain formation mechanism, (c) <100> pole figure of the map, (d) IPF-Z colored map.

Fig. 9. (a) SEM micrograph of the interface with the location for elemental mapping and (b) elemental mapping data across the interface.

Fig. 10. Analysis results at the interface: (a) microstructure of the map area, (b) EDS line scan results identifying the interface, (c) EBSD grain map, and (d) EBSD IPF.

Fig. 11. XRD analysis results on SS316 L and In625.

Fig. 12. Microhardness profile across the whole deposit including the bimetallic interface.

Fig. 13. (a) Stress vs. strain curves for the BAMSs, (b) EDX spot analysis result performed on the fracture surface, (c) fractured surface at low magnification, and higher-magnification image of the fracture surface, (d) at the center, and (e) at the edge.

References 41

[1]	B. Onuike, A. Bandyopadhyay, Addit. Manuf. 22 (2018) 844-851.
[2]	B. Onuike, A. Bandyopadhyay, Addit. Manuf. 27 (2019) 576-585. DOI PMID
[3]	U. Reisgen, R. Sharma, L. Oster, Metals (Basel) 9 (2019) 745. DOI URL
[4]	B.E. Carroll, R.A. Otis, J.P. Borgonia, J. Suh, R.P. Dillon, A.A. Shapiro, D.C. Hofmann, Z.-K. Liu, A.M. Beese, Acta Mater. 19 (2016) 46-54.
[5]	N. Tammasophon, W. Homhrajai, J. Met., Mater. Miner. 21 (2011) 93-99.
[6]	M. Sireesha, S.K. Albert, V. Shankar, S. Sundaresan, J. Nucl. Phys. Mater. Sci. Radiat. Appl. 279 (2000) 65-76.
[7]	G.P. Dinda, A.K. Dasgupta, J. Mazumder, Mater. Sci. Eng. A 509 (2009) 98-104. DOI URL
[8]	P. Varghese, E. Vetrivendan, M.K. Dash, S. Ningshen, M. Kamaraj, U. Kamachi Mudali, Surf. Coat. Technol. 357 (2019) 1004-1013. DOI URL
[9]	X. Chen, J. Li, X. Cheng, B. He, H. Wang, Z. Huang, Mater. Sci. Eng. A 703 (2017) 567-577. DOI URL
[10]	H. Naffakh, M. Shamanian, F. Ashrafizadeh, Metall. Mater. Trans. A 39 (2008) 2403-2415. DOI URL
[11]	A. Hinojos, J. Mireles, A. Reichardt, P. Frigola, P. Hosemann, L.E. Murr, R.B. Wicker, Mater. Des. 94 (2016) 17-27. DOI URL
[12]	R.W. Hertzberg, R.P. Vinci, J.L. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials, 5th edition, Wiley, 2013.
[13]	D.E. Cooper, N. Blundell, S. Maggs, G.J. Gibbons, J. Mater. Process. Technol. 213 (2013) 2191-2200. DOI URL
[14]	G. Marinelli, F. Martina, H. Lewtas, D. Hancock, S. Ganguly, S. Williams, Sci. Technol. Weld. Join. 1718 (2019) 1-9.
[15]	J.S. Zuback, T.A. Palmer, T. DebRoy, J. Alloys. Compd. 770 (2019) 995-1003. DOI URL
[16]	L.D. Bobbio, R.A. Otis, J.P. Borgonia, R.P. Dillon, A.A. Shapiro, Z.K. Liu, A.M. Beese, Acta Mater. 127 (2017) 133-142. DOI URL
[17]	M.R.U. Ahsan, A.N.M. Tanvir, G.J. Seo, B. Bates, W. Hawkins, C. Lee, P.K. Liaw, M. Noakes, A. Nycz, D.B. Kim, Addit. Manuf. 32 (2020), 101036.
[18]	M.R.U. Ahsan, A.N.M. Tanvir, T. Ross, A. Elsawy, M.S. Oh, D.B. Kim, Rapid Prototyp. J. 26 (2019) 519-530. DOI URL
[19]	C. Shen, Application of Wire-Arc Additive Manufacturing (WAAM) Process in In-Situ Fabrication of Iron Aluminide Structures, Ph.D. Thesis, University ofWollongong, 2016.
[20]	J. Rodriguez, K. Hoefer, A. Haelsig, P. Mayr, Metals (Basel) 9 (2019) 620. DOI URL
[21]	A.E. Davis, C.I. Breheny, J. Fellowes, U. Nwankpa, F. Martina, J. Ding, T. Machry, P.B. Prangnell, Mater. Sci. Eng. A 765 (2019), 138289. DOI URL
[22]	G. Marinelli, F. Martina, H. Lewtas, D. Hancock, S. Ganguly, S. Williams, Sci. Technol. Weld. Joining 24 (2019) 495-503. DOI URL
[23]	B. Wu, Z. Qiu, Z. Pan, K. Carpenter, T. Wang, D. Ding, S. Van Duin, H. Li, J. Mater, Sci. Technol. 52 (2020) 226-234.
[24]	T. Abe, H. Sasahara, Precis. Eng. 45 (2016) 387-395. DOI URL
[25]	J.N. Dupont, J.C. Lippold, S.D. Kiser, Welding Metallurgy and Weldability of Nickel-Base Alloys, John Wiley & Sons, 2009.
[26]	M.R.U. Ahsan, Y.R. Kim, R. Ashiri, Y.J. Cho, C.J. Eong, Y.D. Park, Weld. J. 95 (2016) 120-132.
[27]	F. Martina, M. Roy, P. Colegrove, S.W. Williams, in: Annual International Solid Freeform Fabrication Symposium, 2014, pp. 89-94, August 4.
[28]	J.R. Hönnige, P.A. Colegrove, B. Ahmed, M.E. Fitzpatrick, S. Ganguly, T.L. Lee, S.W. Williams, Mater. Des. 150 (2018) 193-205. DOI URL
[29]	F. Martina, M.J. Roy, B.A. Szost, S. Terzi, P.A. Colegrove, S.W. Williams, P.J. Withers, J. Meyer, M. Hofmann, Mater. Sci. Technol. (UK) 32 (2016) 1439-1448.
[30]	B.L. Bramfitt, A.O. Benscoter, Metallographer's Guide: Practice and Procedures for Irons and Steels, ASM International, 2001.
[31]	B. Beausir, J.J. Fundenberger, Available Online www.Atex-Software. Eu (Accessed 22 May-12 June 2019) (2017).
[32]	ASTM E.8, Annu. B. ASTM Stand. 4, 2010, pp. 1-27.
[33]	J.C. Lippold, D.J. Kotecki, Welding Metallurgy and Weldability of Stainless Steels, John Wiley & Sons, 2005.
[34]	X. Chen, J. Li, X. Cheng, H. Wang, Z. Huang, Mater. Sci. Eng. A 715 (2018) 307-314. DOI URL
[35]	A.N.M. Tanvir, M.R.U. Ahsan, C. Ji, W. Hawkins, B. Bates, D.B. Kim, Int. J. Adv. Manuf. Technol. 103 (2019) 3785-3798. DOI URL
[36]	P. Guo, B. Zou, C. Huang, H. Gao, J. Mater. Process. Technol. 240 (2017) 12-22. DOI URL
[37]	J. Nguejio, F. Szmytka, S. Hallais, A. Tanguy, S. Nardone, M. Godino Martinez, Mater. Sci. Eng. A 764(2019).
[38]	M. Dadfar, M.H. Fathi, F. Karimzadeh, M.R. Dadfar, A. Saatchi, Mater. Lett. 61 (2007) 2343-2346. DOI URL
[39]	H. Naffakh, M. Shamanian, F. Ashrafizadeh, J. Mater. Sci. 45 (2010) 2564-2573. DOI URL
[40]	K. Devendranath Ramkumar, R. Sridhar, S. Periwal, S. Oza, V. Saxena, P. Hidad, N. Arivazhagan, Mater. Des. 68 (2015) 158-166. DOI URL
[41]	R. Li, J. Xiong, Rapid Prototyp. J. 25 (2019) 1285-1294. DOI URL